Diverticular Disease. Colorectal Cancer

Content

Introduction ………………………………………………………………………………………..2

Actuality of the topic …………………………………………………………………………………….4

Purpose of thesis……………………………………………………………………………….……4

Objectives of thesis…………………………………………………………………………….…..4

Theoretical importance and value of the work ……………………………………………..……4

Chapter 1 ………………………………………………………………………………………………………5

1.1 General information ………………………………………………….…………….……5

1.1.1. Anatomy of the colon ……………………………………………………….……..5

1.1.2 Blood and nerve supply ……………………………………………………………10

1.2 colorectal cancers …………………………………………………………………………12

1.2.1. Etiopathology ……………………………………………………..…………………….13

1.2.2. Morphopathology …………………………………………………………….…………15

1.2.3. Epidemiology …………………………………………………………………………….17

1.2.4. Types and clinical forms ……………………………….………………………………..18

1.2.5. Stages ……………………………………………………………………………………..20

1.2.6. Signs and symptoms …………………………………………………………………….23

1.2.7. Diagnosis ……………………………………………………………………………….…24

1.2.8. Differential diagnosis ……………………………………………………………………28

1.2.9. Treatment …………………………………………………………………………………29

Introduction

Topic:

Diverticular disease includes diverticulosis or the presence of diverticula protruding through the colonic wall and diverticulitis, an acute inflammation of diverticula associated with fever, leukocytosis, and pain. The conditions annually account for 312,000 admissions and 1.5 million days of inpatient care in the United States. Annual treatment costs in the United States exceed 2.6 billion dollars.

Although diverticular disease is principally a condition that has become widespread in the 20th and 21st centuries, Alexis Littre, a French surgeon, first described it in the late 1700s.3 In 1815, Fleischman coined the term, divertikel, and Jean Cruveilheir described herniations through the muscular layer of the colon in 1849. In 1869, Klebs was the first to link the development of diverticula to constipation. Graser described the inflammation of diverticula, known as diverticulitis in 1899. Mayo and his colleagues first described the surgical management of diverticulosis, but noted that most cases did not require invasive procedures. Beer correlated the clinical and histologic findings of the disorder in 1904; in 1914, Case presented radiographic findings. In 1971, Painter and Burkitt published a milestone article delineating the role of dietary fiber in the prevention of diverticulosis.

Diverticular disease of the colon is common in developed nations. Westernized nations have high prevalence rates of left-sided diverticulosis. Right-sided diverticulosis although rare in Western populations, is more common in Asia, where overall rates of diverticula are much lower. Nonetheless, left-side diverticulosis is still more common in Asia. The presence of right-sided diverticula is considered a distinct disease from left-sided diverticulosis, and is thought to be due largely to genetic predispositions.

Industrialization and development has been shown to increase rates of diverticulosis. In Singapore and in Africa urbanization has led to a higher prevalence of the condition. Rates of diverticulitis are also rising. In Finland, the incidence of diverticulitis has risen 50% in the last two decades, largely in part to reduced dietary fiber and an aging population.

The prevalence of diverticula in colon increases substantially with age. Under the age of 30, only 1 to 2% of patients have diverticulosis.=In early autopsy studies from the 1920s to the 1940s, overall prevalence was reported as 2 to 10%Prevalence increases to 50 to 66% in patients older than age 80 years. Approximately 10 to 25% of patients with diverticulosis will develop diverticulitis.

The prevalence of the disease in men is approximately equal to that of women. McConnell et al reported that diverticular bleeding occurs more commonly in men and strictures and obstructions occur more often in women

Dietary fiber is a mix of complex carbohydrates found in the bran of whole grains and in nuts, seeds, fruits, legumes, and vegetables, but not in any animal foods. Because humans cannot digest these complex carbohydrates, dietary fiber has little caloric value — but it has plenty of health value. Among other things, the insoluble fiber found in wheat bran, whole-grain products, and most vegetables (see table) draws water into the feces, making the stools bulkier, softer, and easier to pass. Dietary fiber speeds the process of elimination, greatly reducing the likelihood of constipation.

A diverticulum  the medical or biological term for an outpouching of a hollow (or a fluid-filled) structure in the body. Depending upon which layers of the structure are involved, they are described as being either true or false.

Purpose of thesis

Study and stabilize the optimal and modern methods of diagnosis and treatment of diverticular disease and identification of the relation between patients age , dietary and geographical location with the development of the disease

Objectives of thesis:

1. study the etiology of diverticulosis

2. search for new modern methods of diagnosis in early stages

3. new aspects for treatment and management

4. the correlation between different factors with the disease

5. prevention of the disease and self awareness

scientific novelty and theoretical importance :

1. to reveal the contemporary researches about the disease and its risk factors

2. to reveal on base of contemporary algorithm the diagnosis and treatment

3. to practice and experience the modern and recent surgical aspect used on base surgical clinics

Values of the work

1. Analyze new material about the development of diverticulum and the etiology factors

2. I have presented a contemporary algorithm of diagnosis and treatment

3. I evaluate an experience at the surgical department at the republican hospital and been with patients having the disease

4. Revealing the most common risk factors correlate with the disease

5. study the modern surgical approach

General information

The colon is the last part of the digestive system in most vertebrates. It extracts waterand salt from solid wastes before they are eliminated from the body and is the site in which flora-aided (large bacterial) fermentation of unabsorbed material occurs. Unlike the small intestine, the colon does not play a major role in absorption of foods and nutrients. About 1.5 litres or 45 ounces of water arrives in the colon each day.

The length of the adult human colon is, on average, for women 155 cm (range of 80 to 214 cm) and for men 166 cm (range of 80 to 313 cm). The average inner circumference of sections of the colon in centimeters (with ranges in parentheses) are cecum 8.7 ,ascending colon 6.6 (6.0-7.0), transverse colon 5.8 (5.0-6.5), descending/sigmoid colon 6.3 (6.0-6.8) and rectum near rectal/sigmoid junction 5.7

Sections of the colon are:

The cecum and the appendix

The ascending colon

The right colic flexure (hepatic)

The transverse colon

The transverse mesocolon

The left colic flexure (splenic)

The descending colon

The sigmoid colon – the v-shaped region of the large intestine

Blood supply

Arterial supply to the colon comes from branches of the superior mesenteric artery (SMA) and inferior mesenteric artery (IMA). Flow between these two systems communicates via a "marginal artery" that runs parallel to the colon for its entire length. Historically, it has been believed that the arc of Riolan, or the meandering mesenteric artery (of Moskowitz), is a variable vessel connecting the proximal SMA to the proximal IMA that can be extremely important if either vessel is occluded. However, recent studies conducted with improved imaging technology have questioned the actual existence of this vessel, with some experts calling for the abolition of the terms from future medical literature.

Venous drainage usually mirrors colonic arterial supply, with the inferior mesenteric vein draining into the splenic vein, and thesuperior mesenteric vein joining the splenic vein to form the hepatic portal vein that then enters the liver.

Innervations :

-3 longitudinal trunks (the taenia coli) create the haustra
-taenia coli end prior to the rectum
-parasympathetic and sympathetic innervation
-vagus proximal part of the colon only,

function of the colon

The large intestine takes about 16 hours to finish the digestion of the food. It removes water and any remaining absorbable nutrients from the food before sending the indigestible matter to the rectum. The colon absorbs vitamins that are created by the colonic bacteria, such as vitamin K (especially important as the daily ingestion of vitamin K is not normally enough to maintain adequate blood coagulation), vitamin B12, thiamine and riboflavin. It also compacts feces, and stores fecal matter in the rectum until it can be discharged via the anus in defecation. The large intestine also secretes K+ and Cl-. Chloride secretion increases in cystic fibrosis. Recycling of various nutrients takes place in colon. Examples include fermentation of carbohydrates, short chain fatty acids, and urea cycling.

The large intestine differs in physical form from the small intestine in being much wider and in showing the longitudinal layer of the muscularis have been reduced to 3 strap-like structures known as the taeniae coli. The wall of the large intestine is lined with simple columnar epithelium. Instead of having the evaginations of the small intestine (villi), the large intestine has invaginations (the intestinal glands). While both the small intestine and the large intestine have goblet cells, they are abundant in the large intestine.

The appendix is attached to the inferior surface of the cecum, and contains a small amount of mucosa-associated lymphoid tissue which gives the appendix an undetermined role in immunity. However, the appendix is known to be important in fetal life as it contains endocrine cells that release biogenic amines and peptide hormones important for homeostasis during early growth and development. The appendix can be removed with no apparent damage or consequence to the patient.

The large intestine extends from the ileocecal junction to the anus and is about 1.5 m long. On the surface, bands of longitudinal muscle fibers called taeniae coli, each about 1/5 in wide, can be identified. There are three bands, and they start at the base of the appendix and extend from the cecum to the rectum. Along the sides of the taeniae, tags of peritoneum filled with fat, called epiploic appendages (or appendices epiploicae) are found. The sacculations, called haustra, are characteristic features of the large intestine, and distinguish it from the small intestine.

The large intestine comes after the small intestine in the digestive tract and measures approximately 1.5 meters in length in adult humans. There are differences in the large intestine between different organisms. The large intestine is mainly responsible for storing waste, reclaiming water, maintaining the water balance, absorbing some vitamins, such as vitamin K, and providing a location for flora-aided fermentation.

By the time the chyme has reached this tube, most nutrients and 90% of the water have been absorbed by the body. At this point some electrolytes like sodium, magnesium, and chloride are left as well as indigestible parts of ingested food (e.g., a large part of ingested amylose, starch which has been shielded from digestion heretofore, and dietary fiber, which is largely indigestible carbohydrate in either soluble or insoluble form). As the chyme moves through the large intestine, most of the remaining water is removed, while the chyme is mixed with mucus and bacteria (known as gut flora), and becomes feces. Theascending colon receives fecal material as a liquid. The muscles of the colon then move the watery waste material forward and slowly absorb all the excess water. The stools gradually solidify as they move along into the descending colon.

The bacteria break down some of the fiber for their own nourishment and create acetate, propionate, and butyrate as waste products, which in turn are used by the cell lining of the colon for nourishment. No protein is made available. In humans, perhaps 10% of the undigested carbohydrate thus becomes available, though this may vary with diet; in other animals, including other apes and primates, who have proportionally larger colons, more is made available, thus permitting a higher portion of plant material in the diet. The large intestine produces no digestive enzymes — chemical digestion is completed in the small intestine before the chyme reaches the large intestine. The pH in the colon varies between 5.5 and 7 (slightly acidicto neutral).

Standing gradient osmosis

Water absorption at the colon typically proceeds against a transmucosal osmotic pressure gradient. The standing gradient osmosis is the reabsorption of water against the osmotic gradient in the intestines. This hypertonic fluid creates an osmotic pressure that drives water into the lateral intercellular spaces by osmosis via tight junctions and adjacent cells, which then in turn moves across the basement membrane and into the capillaries.

Gut flora :

The large intestine houses over 700 species of bacteria that perform a variety of functions, as well as fungi, protozoa, andarchaea. Species diversity varies by geography and diet. The microbes in a human distal gut often number in the vicinity of 100 trillion, and can weigh around 200 grams (0.44 pounds). This mass of mostly symbiotic microbes has recently been called the latest human organ to be "discovered" or in other words, the "forgotten organ".

The large intestine absorbs some of the products formed by the bacteria inhabiting this region. Undigested polysaccharides(fiber) are metabolized to short-chain fatty acids by bacteria in the large intestine and absorbed by passive diffusion. The bicarbonate that the large intestine secretes helps to neutralize the increased acidity resulting from the formation of these fatty acids.

These bacteria also produce large amounts of vitamins, especially vitamin K and biotin (a B vitamin), for absorption into the blood. Although this source of vitamins, in general, provides only a small part of the daily requirement, it makes a significant contribution when dietary vitamin intake is low. An individual who depends on absorption of vitamins formed by bacteria in the large intestine may become vitamin-deficient if treated with antibiotics that inhibit the vitamin producing species of bacteria as well as the intended disease-causing bacteria.

Other bacterial products include gas (flatus), which is a mixture of nitrogen and carbon dioxide, with small amounts of the gases hydrogen, methane, and hydrogen sulfide. Bacterial fermentation of undigested polysaccharides produces these. Some of the fecal odor is due to indoles, metabolized from the amino acid tryptophan. The normal flora is also essential in the development of certain tissues, including the cecum and lymphatics.

They are also involved in the production of cross-reactive antibodies. These are antibodies produced by the immune system against the normal flora, that are also effective against related pathogens, thereby preventing infection or invasion.

The most prevalent bacteria are the bacteroides, which have been implicated in the initiation of colitis and colon cancer.Bifidobacteria are also abundant, and are often described as 'friendly bacteria'.

A mucus layer protects the large intestine from attacks from colonic commensal bacteria

Diverticular disease

Diverticulosis, also known as "diverticular disease", is the condition of having diverticula in the colon, which are out pocketings of the colonic mucosa and submucosa through weaknesses of muscle layers in the colon wall. These are more common in the sigmoid colon, which is a common place for increased pressure. This is uncommon before the age of 40, and increases in incidence after that age

Etiology

The exact etiology of colonic diverticulosis has yet to be fully clarified and many of the claims are only anecdotal. The modern emphasis on the value of fiber in the diet began with Cleave. A strong case was made by Neil Painter and Adam Smith that a deficiency of dietary fiber is the cause of diverticular disease. They argued that the colonic muscles needed to contract strongly in order to transmit and expel the small stool associated with a fiber deficient diet. The increased pressure within the segmented section of bowel over years gave rise to herniation at the vulnerable point where blood vessels enter the colonic wall.

However, the U.S. National Institutes of Health (NIH) considers the fiber theory "unproven." Furthermore, a February, 2012 study in the journal Gastroenterologyfound that "A high-fiber diet and increased frequency of bowel movements are associated with greater, rather than lower, prevalence of diverticulosis." The study involved 2,104 participants, 30–80 years old, who underwent outpatient colonoscopies from 1998 to 2010 and were interviewed regarding diet and physical activity.

Denis Burkitt suggested that the mechanical properties of the colon may be different in the African and the European subjects. He theorized that because Africans eat a diet containing more fiber than Europeans and use the natural squatting position for defecation, they pass bulky stools without straining, and hence rarely if ever develop colonic diverticulosis.

Change in the strength of the colonic wall with age may be an aetiological factor.[19] Connective tissue is a significant contributor to the strength of the colonic wall. The mechanical properties of connective tissue depend on a wide variety of factors, the type of tissue and its age, the nature of the intramolecular and intermolecular covalent cross links and the quantity of the glycosaminoglycans associated with the collagen fibrils. The submucosa of the colon is composed almost entirely of collagen, both type I and type III. Several layers of collagen fibres make up the submucosa of the human colon. The collagen fibril diameters and fibril counts are different between the left and right colon and change with age and in colonic diverticulosis, The implication is that changes normally associated with ageing are more pronounced in colonic diverticulosis. Iwasaki found that the tensile strength of the Japanese colon obtained at postmortem declined with age. Similarly the mechanical properties of the colon are stronger in African than European subjects. However, this race-based claim is contradicted by the virtually identical incidence of diverticular disease in black and white Americans. The strength of the colon decreases with age in all parts of the colon, except the ascending colon. The fall in tensile strength with age is due to a decrease in the integrity of connective tissue. Cross linkage of collagen is increased in colonic diverticulosis. The mucosal layer is possibly more elastic and it is likely that the stiffer external layers break and allow the elastic mucosa to herniate through forming a diverticulum. Collagen has intermolecular and intramolecular cross links which stabilise and give strength to the tissue in which it is located. Accumulation of covalently linked sugar molecules and related increasing cross linking products are found in a variety of tissues with ageing, skin, vascular tissue, the cordae tendinae of heart valves and the colon. This reduces the strength and pliability of the collagen. Colonic diverticulosis increases in frequency with age. There is a reduction in the strength of the colonic mucosa with age, and that increased contractions in the descending and sigmoid colon secondary to an insufficient fibre content of the diet cause protrusion through this weakened wall. Colonic diverticulosis is in general a benign condition of the bowel which uncommonly becomes symptomatic and even less commonly becomes a truly clinical complicated problem.

Disordered Intestinal Motility

In the 1960s, Arfwidsson et al performed manometry on subjects with and without sigmoid diverticula, and showed higher luminal pressures in those with diverticular disease. Painter and colleagues confirmed these results and performed simultaneous cineradiography. They discovered that under normal circumstances, haustral contractions occur simultaneously creating isolated compartments or “small bladders” that can generate locally high pressures. This process is called segmentation. The researchers suggested that physiologically, segmentation aids in water reabsorption and electrolyte balancing, but could also cause locally increased pressures that could lead to herniation and the formation of diverticula. This effect can be increased by a lack of dietary fiber.

Painter showed that the basal pressure of the sigmoid is a few millimeters of mercury above atmospheric pressure in both patients with and without diverticular disease. However, high pressure waves that normally have an amplitude of 10 mm Hg can have amplitudes as high as 90 mm Hg in patients with symptomatic diverticular disease. High right-sided pressures are also associated with right-sided diverticular disease. Although the associations are clear, it has been difficult for researchers to directly link high intraluminal pressures to the development of diverticula due to inherent methodologic difficulties.

Studies have shown that myoelectrical patterns differ in patients with diverticular disease compared with healthy subjects. Specifically, patients with diverticulosis exhibit slow wave motility patterns of 12 to 18 cycles per minute, distinctly different from the 3 cycles per minute pattern observed in irritable bowel syndrome. Intake of bran normalizes motility patterns in patients with diverticular disease, but abnormal patterns persist after bran administration in patients with irritable bowel syndrome.

In addition to myoelectrical aberrations, studies show hypermotility in the descending and sigmoid colon of patients with diverticular disease. In 2001, Bassotti and colleagues performed 24-hour manometry on patients with diverticular disease and normal controls. They found that patients with diverticular disease displayed significantly increased amounts of motility in the affected segments compared with control subjects; in the diverticular disease group, response to a physiologic stimulus (meal) was also abnormal. They also observed increased amounts of disorganization and retrograde propagation of propulsions in the diverticular disease group.

The complex role of chemical mediators on colonic motility in diverticular disease has been investigated. Tomita et al noted that the diverticular colon is more strongly innervated by cholinergic nerves than the normal colon; nonadrenergic, noncholinergic inhibitory nerves act to a lesser extent in the diverticular colon; and that nitric oxide mediates the relaxation reaction of nonadrenergic, noncholinergic inhibitory nerves to a lesser extent in the diverticular colon. A study by Milner and colleagues revealed that vasoactive intestinal polypeptide (VIP) content of the mucosa and whole wall was increased in diverticular disease. They noted that VIP was unaltered in the circular muscle and taenia coli, and that substance P and neuropeptide Y levels in all layers of colonic wall were unaltered in diverticular disease. A study by Costedio and colleagues evaluated the role serotonin (5-HT) plays in diverticular disease. Serotonin is known to be a primary trigger of gut motility. They found that serotonin levels were comparable in patients with and without diverticular disease, but that patients with a recent history of acute diverticulitis have significant attenuation of the 5-HT transporter, possibly accounting for delayed return of normal gastric motility after the resolution of inflammation in diverticulitis. Although a large number of chemical mediators have been linked to colonic motility, their role in diverticular disease has not been well elucidated.

Dietary Fiber Deficiencies

In 1969, Painter and Burkitt popularized the theory that diverticular disease is due to a dietary deficiency in fiber, and that risks and rates of diverticulosis could be decreased by dietary changes. They studied over 1,200 individuals in the United Kingdom and in Uganda, and noted vast differences in diet, most strikingly in fiber intake. Longer stool transit times and lower stool weights were seen in the UK population, correlating with increased rates of diverticular disease.

A wide body of evidence has emerged that supports this theory. Fiber is thought to lower intracolonic pressures, speed transit times, increase stool weight and volume, and contribute to more frequent bowel movements. The increased consumption of refined sugar and white flour, beginning in the Industrial Revolution coincided with decreases in dietary fiber intake. A sharp increase in diverticular disease in Western populations occurred ~40 years later, when the children first raised on the new “industrialized” diet became middle-aged.41 Mendeloff criticized this theory as oversimplified, and subsequent research has failed to show differences in stool transit time and volume between Westerners who have diverticular disease and those who do not. Researchers have found, however, a negative association between consumption of fiber and the development of diverticular disease.

Animal studies done by Fisher and colleagues showed that only 9% of rats fed diets rich in fiber developed diverticulosis as compared with 45% of those fed a low-fiber diet. Another animal model noted that rats fed high-fiber diets not only exhibited lower rates of diverticulosis, but were protected against collagen crosslinking in the colonic wall. The same group noted that maternal diets rich in fiber were also associated in lower rates of diverticulosis in rat offspring.

Studies have shown that in patients with diverticular disease implementing a diet high in fiber improves transit time in as little as 1 month. Taylor and Duthie reported that after supplementing diverticular disease patients with bran tablets, stool weight increased, electrical rhythms improved, hypermotility decreased, and symptoms improved.

Additional Factors

INFLAMMATION

Although inflammation is certainly the major component of complicated diverticular disease, including diverticulitis, new evidence suggests that inflammation may also play a role in the early pathogenesis of the disease.

Morphopathology :

The development of diverticula in the colon typically occurs in parallel rows between the taenia coli. The pathogenesis of the disorder involves three major areas: ] structural abnormalities of the colonic wall, ] disordered intestinal motility, and ] deficiencies of dietary fiber. Additional factors have also been linked to diverticular disease.

Structural Abnormalities

The colon, unlike the small intestine and rectum, contains only one complete muscular layer, the inner circular layer. The outer longitudinal layer is concentrated in the three taeniae coli. Together these two layers form the muscularis propria. One of the taeniae coli is on the mesenteric aspect (taenia mesentericus) and the other two are located on the medial and lateral aspects of the bowel wall (taeniae omentalis and libra). The vasa recta, blood vessels from the mesentery, supply the mucosa and submucosal tissues.

The colonic wall is weakest at the points between the mesenteric and antimesenteric teniae where the vasa recta penetrate the muscle. Microscopic studies have revealed muscle atrophy at these sites, which are naturally susceptible to herniation.18 Diverticula often form at these areas of weakness, bulging through the circular muscle, but rarely through the taeniae.

As compared with healthy controls, the gross and microscopic anatomy of the colonic wall in patients with diverticular disease shows striking differences. Marked thickening of the circular muscle, shortening of the tenia, and narrowing of the lumen is seen in patients with diverticular disease.

Thickening of the circular muscle is not due to muscle hypertrophy or hyperplasia, but instead from abnormal elastin deposition. Whiteway and Morson demonstrated that elastin content of the taeniae coli increases by greater than 200% in patients with diverticular disease compared with controls.24 This leads to characteristic shortening of the muscle layer and an accordion-like effect known as concertina; it is found in the two-thirds of the bowel between the mesenteric and antimesenteric taeniae where diverticula are prominently found.

Abnormal collagen cross-linking has been observed in the colonic walls of patients with diverticular disease. Increased levels of collagen cross-linking are seen in normal aging, especially after age 40 when rates of diverticulosis increase. When compared with age-matched controls, studies have shown that the patients with diverticular disease have greater rates of collagen cross-linking.

The association of increased collagen cross-linking and the development of colonic diverticula is supported by the observation that patients with connective tissue disease such as Ehlers–Danlos or Marfan syndrome who have similar abnormalities of collagen cross-linking also develop diverticulosis earlier in life. It is hypothesized that increased collagen cross-linking decreases compliance leading to stiffer tissue that is more susceptible to tears, especially under conditions of increased luminal pressures.

Epidemiology

Diverticular disease of the colon is common in developed nations. Westernized nations have high prevalence rates of left-sided diverticulosis. Right-sided diverticulosis although rare in Western populations, is more common in Asia, where overall rates of diverticula are much lower. Nonetheless, left-side diverticulosis is still more common in Asia. The presence of right-sided diverticula is considered a distinct disease from left-sided diverticulosis, and is thought to be due largely to genetic predispositions.

Industrialization and development has been shown to increase rates of diverticulosis. In Singapore and in Africa14 urbanization has led to a higher prevalence of the condition. Rates of diverticulitis are also rising. In Finland, the incidence of diverticulitis has risen 50% in the last two decades, largely in part to reduce dietary fiber and an aging population.15 The prevalence of diverticula in colon increases substantially with age. Under the age of 30, only 1 to 2% of patients have diverticulosis. In early autopsy studies from the 1920s to the 1940s, overall prevalence was reported as 2 to 10%. Prevalence increases to 50

Classification and clinical forms

Current classifications of DD are based on localization, distribution, symptoms, clinical presentation and pathology Two different types of classification have been proposed: a clinical classification and the Hinchey classification[41], which is used to describe the stages of perforated DD

Classification of diverticular diseases of the colon

However, the hallmark of painful DD is abdominal pain in the absence of any indications of inflammation. Pain is usually colicky, but may also be steady. It is exacerbated by eating, and is typically relieved by flatus or bowel movements.

Clinical and laboratory diagnosis

In cases of asymptomatic diverticulosis, the diagnosis is usually made as an incidental finding on other investigations.

While a good history is often sufficient to form a diagnosis of diverticulosis or diverticulitis, it is important to confirm the diagnosis and rule out other pathology (notably colorectal cancer) and complications.

Investigations

Plain abdominal X-ray may show signs of a thickened wall, ileus, constipation, small bowel obstruction or free air in the case of perforation. Plain X-rays are insufficient to diagnose diverticular disease.

Contrast CT is the investigation of choice in acute episodes of diverticulitis and where complications exist.

Colonoscopy will show the diverticulum and rule out malignancy. A colonoscopy should be performed 4–6 weeks after an acute episode.

Barium enema is inferior to colonoscopy in terms of image quality and is usually only performed if the patient has strictures or an excessively tortuous sigmoid colon where colonoscopy is difficult or dangerous.

MRI provides a clear picture of the soft tissue of the abdomen, however its expense often outweighs the benefits when compared to contrast CT or colonoscopy.

There is no blood test for diverticulosis.

It is important to note that both barium enema and colonoscopy are contraindicated during acute episodes of diverticulitis, as the barium may leak out into the abdominal cavity, and colonoscopy can cause perforations of the bowel wall.

Signs and Symptoms

Diverticulosis can present with

1. Painless rectal bleeding as bright red blood per rectum

2. Cramps and tenderness may also occur in the affected areas.

3. Constipation

4. Diarrhea

Most people with colonic diverticulosis are unaware of this structural change. When symptoms do appear in a person over 40 years of age it is important to obtain medical advice and exclude more dangerous conditions such as cancer of the colon or rectum.[2][3][4][5]

The clinical forms of colonic diverticulosis are:

Uncomplicated

Some patients with diverticulosis complain of symptoms such as cramping, bloating, flatulence, and irregular defecation. However, it is unclear if these symptoms are attributable to the underlying diverticulosis or to coexistent irritable bowel syndrome.[6]

Complicated large intestines

This is very uncommon but highly dangerous. The diverticula may bleed, either rapidly (causing bleeding through the rectum) or slowly (causing anemia). The diverticula can become infected and develop abscesses, or even perforate. These are serious complications and medical care is needed. Infected diverticula and development of abscesses merits the term diverticulitis. First time bleeding from the rectum, especially in individuals aged over age 40, could be due to colon cancer, colonic polyps and inflammatory bowel disease rather than diverticulosis and requires clinical investigation

Differential diagnosis:

1. Acute abdomen

2. Perforation / rupture of hollow organ (colon, small intestine, gastric ulcer, gallbladder

3. Acute pancreatitis

4. Intra-abdominal abscess

5. Carcinoma of the colon (CRC)

6. IBS

7. IBD

8. pseudo-membranus colitis

9. Other infectious colitides

10. Appendicitis

11. Ischemic colitis

12. Acute Gastritis

13.Acute Pyelonephritis

14. Biliary Colic

15.Biliary Disease

16.Biliary Obstruction

17.Cholangitis

18.Chronic Mesenteric Ischemia

19. Colonic Obstruction

20.Constipation

21.Cystitis in Females

22.Enterovesical Fistula

23.Gynecologic Pain

24.Inflammatory Bowel Disease

TREATMENT :

Non-surgical treatment

Effects of rifaximin (R) administration on symptoms in patients with diverticular disease

There is a general consensus that conservative treatment is indicated in cases with newly onset uncomplicated diverticulitis[5,38,62,63]. The rationale for this strategy is that about 50%-70% of patients treated for a first episode of acute diverticulitis will recover and have no further clinical problems. Furthermore, only about 20% of these patients will develop symptoms whilst those with recurrent symptoms have a 60% risk of developing disease complications[5,44].

In patients with uncomplicated diverticulosis, a diet with abundant fruit and vegetables is recommended since it seems that this protective effect reduces symptom development and prevents major complications as demonstrated in uncontrolled studies. Nevertheless, recent guidelines[38] advise the use of a high fibre diet, which should be prescribed also for the well-known potential health benefits.

Anticholinergic and antispasmodic agents may be effective in some cases of uncomplicated DD. However, their use remains to be confirmed by controlled studies.

Although the role of antibiotics in uncomplicated DD is still debated[38], recent clinical studies[64-66] have demonstrated that cyclic administration of rifaximin (Normix®, Alfa Wassermann S.p.A., Alanno Scalo, Chieti, Italy) (a broad-spectrum poorly absorbable antibiotic) is more effective in reducing symptoms than fibre supplementation alone

Effects of rifaximin (R) administration on symptoms in patients with diverticular disease

Latella et al[66] performed a large, multicentre, prospective, randomized study, enrolling 968 outpatients with symptomatic diverticulosis. Among them, 595 patients received fibre supplement (glucomannan 4 g/d) plus rifaximin 400 mg bid for 7 d, per month, and 373 patients received glucomannan alone. After 12 mo, a significant reduction in the occurrence rate of symptoms was documented in the group treated with rifaximin and fibre. 56.5% of the patients were asymptomatic as compared to 29.2% of the fibre group. Moreover, the incidence of major complications was lower in the rifaximin plus fibre group vs the group treated with fibre alone. The mechanism of of rifaximin in reducing the frequency of symptoms and the rate of complications of DD is only speculative. It has been suggested that rifaximin reduces the metabolic activity of intestinal bacterial flora, the degradation of dietary fibres, and the production of gas. The latter effect is important since an increased production of intestinal gas and of gas-related symptoms such as pain and bloating have recently been documented, in patients with IBS[67]. Furthermore, treatment with non-absorbable antibiotics was shown to reduce symptoms frequency and intensity in these patients. Similar results were obtained by others[68] who documented an association between small intestinal overgrowth and functional intestinal disorders. Moreover, eradication of bacterial overgrowth seems to be related to a reduction in intestinal symptoms

Surgery:

If symptoms of diverticulitis are frequent, or the patient does not respond to antibiotics and resting the colon, the doctor may advise surgery. The surgeon removes the affected part of the colon and joins the remaining sections. This type of surgery-partial colectomy-aims to prevent complications and future diverticulitis. The doctor may also recommend surgery for complications such as a fistula or partial intestinal obstruction.

Immediate surgery may be necessary when the patient has other complications, such as perforation, a large abscess, peritonitis, complete intestinal obstruction, or severe bleeding. In these cases, two surgeries may be needed because it is not safe to rejoin the colon right away.

During the first surgery, the surgeon cleans the infected abdominal cavity, removes the portion of the affected colon, and performs a temporary colostomy, creating an opening, or stoma, in the abdomen.

The end of the colon is connected to the opening to allow normal eating while healing occurs. Stool is collected in a pouch attached to the stoma. In the second surgery several months later, the surgeon rejoins the ends of the colon and closes the stoma

Complications :

Bleeding

Around 15% of people with diverticular disease or diverticulitis experience bleeding, which is usually painless, quick and resolves itself in 70-80% of cases.

However, if the bleeding does not resolve itself, an emergency blood transfusion may be required due to excessive bleeding. If the bleeding is severe, you may need to be admitted to hospital for monitoring.

Urinary problems

Diverticulitis can lead to the inflamed part of the bowel being in contact with the bladder. This may cause urinary problems, such as:

pain when urinating (dysuria)

needing to urinate more often than usual

in rare cases, air in the urine

Abscess

The most common complication of diverticulitis is an abscess outside the large intestine (colon). An abscess is a pus-filled cavity or lump in the tissue. Abscesses are usually treated with a technique known as percutaneous abscess drainage (PAD).

A radiologist (a specialist in the use of imaging equipment, such as computerised tomography (CT) scans) uses an ultrasound or CT scanner to locate the site of the abscess.

A fine needle connected to a small tube is passed through the skin of your abdomen (stomach) and into the abscess. The tube is then used to drain the pus from the abscess. A PAD is performed under a local anaesthetic.

Depending on the size of the abscess, the procedure may need repeating several times before all the pus has been drained. If the abscess is very small – usually less than 4cm (1.5in) – it may be possible to treat it using antibiotics.

Read more about treating abscesses.

Fistula

A fistula is another common complication of diverticulitis. Fistulas are abnormal tunnels that connect two parts of the body together, such as your intestine and your abdominal wall or bladder.

If infected tissues come into contact with each other, they can stick together. After the tissues have healed, a fistula may form. Fistulas can be potentially serious as they can allow bacteria in your large intestine to travel to other parts of your body, triggering infections, such as an infection of the bladder (cystitis).

Fistulas are usually treated with surgery to remove the section of the colon that contains the fistula.Peritonitis

In rare cases, an infected diverticulum (pouch in your colon) can split, spreading the infection into the lining of your abdomen (perforation). An infection of the lining of the abdomen is known as peritonitis.

Intestinal obstruction

If the infection has badly scarred your large intestine, it may become partially or totally blocked. A totally blocked large intestine is a medical emergency because the tissue of your large intestine will start to decay and eventually split, leading to peritonitis.

A partially blocked large intestine is not as urgent, but treatment is still needed. If left untreated, it will affect your ability to digest food and cause you considerable pain.

Intestinal blockage from diverticular disease is very rare. Other causes, such as cancer, are more common. This is one of the reasons your GP will investigate your symptoms.

In some cases, the blocked part can be removed during surgery.

However, if the scarring and blockage is more extensive, a temporary or permanent colostomy may be needed.

Contemporary management and treatment

Clinical presentation and investigation of acute diverticulitis

Patients with acute diverticulitis typically present with acute onset of abdominal pain, localized in the left lower quadrant. Peritoneal irritation may cause localized tenderness with voluntary guarding and rebound found on clinical examination. Occasionally, if a patient has a long, redundant loop of sigmoid colon, the patient may present with right lower quadrant pain as the redundant loop crosses the midline to the right side. Acute diverticulitis should particularly be considered in the differential when an older patient presents with right lower quadrant pain. Classically, patients will have a fever and laboratory studies may show a leukocytosis (predominantly neutrophilia) with elevation of inflammatory markers.

The contemporary mainstay of diagnosis is Computed Tomography (CT) of the abdomen and pelvis; it remains an invaluable adjunct to clinical impression, helps to rule out differential diagnoses, grade the severity of disease, and guide clinical management. We generally recommend against colonoscopy in the acute setting because of the risk of perforating an already inflamed colon with gas insufflation. However, in selected patients in whom the diagnosis is unclear, to rule out pathology such as colon cancer, acute ischemia, or pseudomembranous colitis a gentle flexible sigmoidoscopy may be undertaken

Evolution in the classification systems used for acute diverticulitis

There are two main classification modalities for grading the severity of diverticulitis. The more traditional Hinchey Classification grades sigmoid diverticulitis based on findings at surgery12 (see Table 1) and was first described in 1978. The major flaw of the Hinchey classification is that it is not applicable to the majority of patients with diverticulitis who can be managed with antibiotics and do not require surgery. Several modifications of the Hinchey grading system have therefore been proposed. Among them, a European consensus conference on diverticular disease has proposed a subclassification of Hinchey grade II diverticulitis, divided into grade IIA, corresponding to a distant abscess amenable to percutaneous drainage and grade IIB, which is a complex abscess with or without an associated fistula.13 Another recent advancement in the classification of sigmoid diverticulitis has been introduced by Ambrosetti and colleagues who described the severity of diverticulitis based on CT findings as moderate or severe diverticulitis14 (see Table 2). Moderate disease is present when inflammation of the pericolic fat is associated with sigmoid colon wall thickness greater than 5 mm. Severe disease is moderate disease plus at least one of either abscess, free extraluminal gas, or contrast extravasation from the colon.15 Chautems et al reported their experience with acute diverticulitis diagnosed by CT in a cohort of 118 patients, followed for a median of 9.5 years. Their data showed that young age (<50) and severe diverticulitis diagnosed on CT scan were independent predictors of poor outcome (P = 0.007 and P = 0.003, respectively). Using this data the authors advocate offering elective surgery to young patients with severe disease on CT scan

Hinchey classification of acute diverticulitis and its modifications

Ambrosetti classification 15

Management of uncomplicated acute diverticulitis

In the event of localized sigmoid diverticulitis, with inflammation of the sigmoid colon, the basic tenet of management is administration of broad-spectrum antibiotics. Typically, younger patients who are systemically well with no comorbidity can be managed with oral antibiotics in the outpatient setting. However, older patients, patients with signs of systemic toxicity or significant comorbidity may warrant hospital admission for intravenous antibiotics. However, admission to hospital with acute diverticulitis requiring intravenous antibiotics remains associated with good outcomes.17,18 After initiation of intravenous antibiotic therapy one should see an appropriate drop in white blood cell count and temperature.18,19 The vast majority of patients with uncomplicated diverticulitis will recover without incident. Current studies are focusing on the identification of possible predictors of patients who are at higher risk of recurrence. Hall et al, in following a cohort of 672 patients after their first attack of uncomplicated diverticulitis for a mean follow-up of 48 months, found an overall recurrence rate of 36% at 5-year follow-up. Predictors of recurrence included family history, long segment of diseased colon (>5 cm), and history of retroperitoneal abscess at first presentation.20 A small proportion of patients will fail to respond to nonoperative management and experience worsening symptoms. This group of patients may require surgery during the same hospital stay or an expedited elective procedure performed 6 weeks after the acute attack of diverticulitis.

In the majority of patients who recover from an acute attack and are discharged from the hospital, it is critical to exclude other conditions, particularly malignancy, on follow-up. Thus, if the patient has not had a recent colonoscopy it is advisable to schedule one after resolution of the acute attack.

Evolution in the indications for elective surgery

For many years, the traditional surgical teaching was that an elective sigmoid colectomy should be advised after a second attack of uncomplicated diverticulitis. This principle was based on the assumption that after two episodes of diverticulitis, subsequent disease attacks were inevitable and that surgical resection removed the risk of recurrence presenting acutely with a potentially life-threatening colonic perforation. However, more recent data has challenged the traditional indications for elective resection. Chapman and colleagues reported that patients with more than two prior episodes of diverticulitis were not at increased risk of developing complicated diverticulitis (defined as diverticulitis with perforation, obstruction, abscess, fistula, bleeding, or phlegmon).21Their data demonstrated that morbidity and mortality rates in patients with recurrent diverticulitis were equivalent to that seen in patients who presented with complicated diverticulitis at first presentation. Other studies have confirmed that clinical presentation of free perforation mostly occurs as the first episode of disease and that avoidance of surgery after two episodes is not associated with an increase in emergency surgery and may result in reduced health care costs.22–24 The indication for colectomy should therefore not be made based on the potential risk of free perforation. In this respect, the American Society of Colon and Rectal Surgeons (ASCRS) guidelines for elective sigmoid colectomy recommend that “the number of attacks of uncomplicated diverticulitis is not necessarily an overriding factor in defining the appropriateness of surgery”. Rather, the decision to operate on uncomplicated disease should be individualized taking into account patient age, medical comorbidity, frequency and severity of attack(s), and persistence of symptoms after resolution of the acute infection.25 As a result, the number of patients undergoing elective resection for acute, uncomplicated diverticulitis is falling. Data from the National Inpatient Sample evaluating 685,390 hospital discharges with a diagnosis of acute diverticulitis over a 15-year time period ending in 2005 indicates that the number of patients with diverticulitis per 1000 hospital discharges increased but the proportion of patients undergoing colectomy for uncomplicated diverticulitis significantly decreased from 17.9% in 1991 to 13.7% in 2005. Over the study period the proportion of patients with diverticular abscess increased from 5.9% to 9.6% but the percentage of patients with free perforation was unchanged at 1.5% and the number of perforations/abscesses treated by colectomy declined from 71% to 55.5%.3 Occasionally patients with recurrent acute diverticulitis may present with symptoms of large bowel obstruction due to stricturing disease, a sequela of recurrent attacks of inflammation that heal by fibrosis.

Elective surgical management of uncomplicated diverticular disease

The goal of surgery is to remove the diseased sigmoid colon in its entirety, fashioning an anastomosis between the soft, proximal remnant left colon and the upper rectum recognized by the confluence of the teniae. Failure to resect the entire sigmoid colon is associated with a four-fold increased likelihood of developing recurrent diverticulitis.28,29 Takedown of the splenic flexure is often required, although not mandatory, to facilitate a tension-free anastomosis. Identification of the ureter is mandatory prior to vessel ligation. Ligation of the inferior mesenteric artery at the origin is not absolutely necessary and might be associated with a period of anorectal malfunction (as long as 6 months) characterized by diarrhea, urgency to defecate, tenesmus, or inability to discriminate between gas and stool.30 There is no strong data to support the results of this study as quality of life and functional outcomes after sigmoidectomy are generally excellent.31 At times the degree of inflammation in the left lower quadrant may be significant. Perioperative ureteric stenting should be considered in such cases. If an inflammatory phlegmon is encountered it is possible to identify the ureter proximally, often as far cephalad as the renal hilum and follow it distally. This allows safe delineation of the ureter in relation to the inflammatory process, allowing safe mobilization and division of the colon. In such patients, we have a low threshold for a proximal diverting loop ileostomy. Some debate remains regarding the optimal timing of surgery in acute diverticulitis. Some centers advocate operating on the same hospital admission to reduce hospital stay and possible re-admissions with acute diverticulitis in the window period prior to planned surgery.32 Natarajan et al, in reviewing their series of laparoscopic sigmoid colectomy for diverticular disease, did not find any association between timing of surgery, complication rate, operative time, recovery period, or conversion to open.33 On the other hand, other series have indicated that early surgery was associated with a significant increase in conversion rate (37.7% vs 12.9%, P < 0.001) and longer hospitalization (13.5 vs 10.5 days; P < 0.001).34 A prospective German study evaluating the optimal timing of laparoscopic sigmoid resection for uncomplicated and complicated diverticular disease showed that patients having early surgery (4–8 days after initiation of antibiotic therapy, n = 244) incurred in an increased number of conversions (9.7% vs 0.9%), increased minor morbidity (25.9% vs 12.9%) and wound infection rates (16.4% vs 4.6%) than patients who had delayed surgery.35Based on this data we continue favoring delaying elective surgery by an interval of 4–6 weeks after the latest disease episode.

Evolution in operative approach – from open surgery to minimally invasive techniques

With the advent of minimally invasive surgery, the laparoscopic and single incision approaches are being increasingly utilized. Many data support that the laparoscopic approach to diverticular disease is associated with accelerated postoperative recovery. A meta-analysis of 19 studies comparing open and laparoscopic sigmoid colectomy has shown equivalence in the incidence of medical complications, rehospitalization or reoperation. In addition, the laparoscopic approach was associated with fewer wound complications (P < 0.05), blood transfusions (P < 0.01) and postoperative ileus rates (P< 0.01).36 Furthermore, data from our group has previously indicated that laparoscopic surgery is cost-effective.37 A prospective, randomized, single-blinded comparison of open and laparoscopic sigmoid colectomy recently published confirms that the laparoscopic approach is associated with a 30% reduction in duration of postoperative ileus and hospital stay; the median duration of procedure was 165 minutes in the laparoscopy group and 110 minutes in the open group (P < 0.0001). In contrast with this, the median delay between surgery and first bowel movement was 76 hours in the laparoscopy group vs 105 hours in the open group (P < 0.0001). The median score for maximal pain assessed by a visual analog scale was 4 in the laparoscopy group vs 5 in the open group (P = 0.05). Finally, the median duration of hospital stay was 5 days in the laparoscopy group vs 7 days in the open group (P < 0.0001).38 Another prospective randomized controlled trial, the Sigma trial, also showed similar benefits for laparoscopic surgery over open resection. Laparoscopic resection again took longer (P = 0.0001) but was associated with decreased intraoperative blood loss. Moreover, there were significantly more major complications in the open sigmoid colectomy group (9.6% vs 25.0%; P = 0.038). Patients undergoing laparoscopic resection also reported less pain, required reduced doses of systemic analgesia, returned home earlier, and experienced a significantly better quality of life.39 Very little data exists regarding Hand Assisted Laparoscopic Surgery (HALS), other than a systematic review and meta-analysis of HALS and laparoscopic colorectal surgery in general, which found HALS to be associated with reduction in both operating time and conversion rates, particularly pertaining to diverticulitis.40 HALS might be particularly suitable for extensively inflamed, adherent, or fistulizing sigmoid colon disease. More recently, several short series on single incision laparoscopic surgery (SILS) sigmoid colectomy for diverticular disease have been published;41,42 however, these series are small and the procedure is still in its embryonic stages, thus we cannot comment on its utility in diverticular disease other than to say that it has promise

The evolution of alternative surgical management for Hinchey III diverticulitis: laparoscopic lavage

Laparoscopic peritoneal lavage was first described by O’Sullivan and colleagues in eight patients with purulent generalized peritonitis, none of whom required further surgical intervention during 48 months of follow-up. This original report from 1996 prompted a prospective, multi-institutional Irish study of 100 patients with purulent peritonitis following diverticular perforation. Patients had laparoscopic evaluation of the peritoneal cavity, lavage with 4 L of warm saline solution and no resection. The selective use of drains was left to the individual surgeon’s discretion with feculent peritonitis or a visible opening in the sigmoid as contraindications to this approach. Morbidity and mortality rates were 4% and 3%, respectively. Only two patients (2.2%) required subsequent percutaneous drainage of a pelvic abscess. At median follow-up of 36 months, only two patients (2.2%) presented with recurrent diverticulitis.80 This study prompted several other groups to assess the feasibility of laparoscopic lavage for Hinchey III diverticulitis. An Australian group has shown similarly encouraging data, with eight out of 27 patients (29.6%) treated with laparoscopic lavage developing recurrent complicated diverticulitis requiring elective surgical resection. A further 29.6% (8/27) had an uncomplicated postoperative course with early, planned resection. The remaining patients (11/27, 40.8%) had no further sequelae at a mean follow-up of 20 months.81 A retrospective, comparative French study evaluated the outcomes of patients with Hinchey III diverticulitis treated by laparoscopic lavage (n = 24) compared with those in whom resection and anastomosis (n = 35) was undertaken. The results showed that the median hospital stay was lower in patients treated by laparoscopic peritoneal lavage (8 vs 17 days, P < 0.0001). Twenty-five patients in the laparoscopic peritoneal lavage group subsequently underwent elective laparoscopic resection, with only one case converted to laparotomy. Cumulative surgical morbidity (16% vs 37.5%, P = 0.0507) and hospital stay (14 vs 23 days, P < 0.0001) was less in the laparoscopic peritoneal lavage group.82A noteworthy, potential advantage of laparoscopic lavage is that it may reduce the number of patients requiring an ostomy by converting an emergency resection with proximal stoma/colostomy to an elective laparoscopic sigmoid colectomy with primary anastomosis. In addition, a significant proportion of patients having successful laparoscopic lavage may not require definitive surgery at all. The true value of this new technique will become evident once the results of a randomized controlled trial, the Lapland Study (http://clinicaltrials.gov/ct2/show/study/NCT01019239?term=lapland&rank=1), an Irish-based multi-institutional prospective RCT, become known.