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Diverticulosis
Diverticulosis are outpocketings of the colonic mucosa and submucosa  and are  found most frequently in the left colon, especially in the sigmoid colon. This is uncommon before the age of 40, and increases in incidence after that age. The diverticulae form through weaknesses of muscle layers created by  the entry of blood vessels from the mesentery supporting the bowel.. The diverticula are of a pulsion type, that is a pouch of mucus membrane projecting through the circular muscle layers to the pericolic fat and appendices epiploicae on the underside of the colon between the mesenteric and medial and lateral antimesenteric taeniae. Diverticulosis is in general a benign condition but can become symptomatic or complicated. It is important to differentiate benign diverticulosis from diverticulitis 1 Signs and symptoms 2 Causes 3 Diagnosis 4 Management 6 Epidemiology 7 References 8 External links

Signs and symptoms
Most people with colonic diverticulosis are unaware of this structural change. When symptoms do appear in a person over 40 years of age then it is important to obtain medical advise and investigations  to exclude more dangerous conditions eg cancer of the colon or rectum.

The clinical forms of colonic diverticulosis are

Symptomatic colonic diverticulosis
. This is the commonest complication of colonic diverticulosis. This is when the motility, that is the onward propulsive nature of contractions in the bowel become disorganised and even spasm can develop. This results in pain in the left lower abdomen and often is accompanied by the passage of small pelletty stools and slime which relieves the pain, Symptoms can consist of, 1.bloating, 2.changes in bowel movements (diarrhoea or constipation). 3.Non-specific chronic discomfort in the lower left abdomen, with occasional acute episodes of sharper pain. 4.abdominal pain, often after meals often in the left lower abdomen If these persist clinical investigation is advised.

Complicated colonic diverticulosis
. This is very uncommon but highly dangerous. The diverticulae may bleed either  rapidly or slowly as a cause of anaemia. The diverticulae can become infected and develop abscesses or even perforate. These are serious complications and medical care is needed. Only infected diverticulae 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 rather than  diverticulosis.

2. Aetiology
A diet without sufficient fiber makes the stools small, requiring the bowel to squeeze harder to move the smaller stool along the bowel.

Risk factors


1.increasing age 2.constipation 3.a diet that is low in dietary fiber content or high in fat 4. high intake of meat and red meat connective tissue disorders that may cause weakness in the colon wall (such as Marfan syndrome). The exact aetiology of colonic diverticulosis has yet to be fully clarified and many of the claims are only anecdotal . . The modern emphasis on the value of fibre in the diet began with Cleave. A strong case was made by Neil Painter  and Adam Smith that a deficiency of dietary fibre 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 fibre 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. Denis Burkitt had suggested that the mechanical properties of the colon may be different in the African and the European subjects. Because Africans eat a diet containing much more fibre than Europeans they pass bulky stools, and hence rarely if ever develop colonic diverticulosis , However changes in the strength of the colonic wall with age is an important aetiological factor  13. Eastwood MA (1998) Structure and function of the colon. In Encyclopedia of Human Nutrition, pp. 945-953 [MJ Sadler, JJ Strain and B Caballero, editors). San Diego, CA: Academic Press. . 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 being that changes which are normally associated with ageing are more pronounced in colonic diverticulosis. Iwasaki found that the tensil strength of the Japanese colon obtained at postmortem declined with age. . Similarly the mechanical properties of the colon are stronger in African than European subjects18. 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 that increased contractions in the descending and sigmoid colon secondary to a 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.

3. Diagnosis
Barium enema or colonoscopy are the most used test for diagnosis. This is important for treatment and investigation of other diseases. Other tests include abdominal X-ray, CT, or MRI. Note that if Diverticulitis (inflammation of the diverticula) is suspected, both colonoscopy and barium enema require extremely skilled hands.

4. Management
Many patients with diverticulosis have minimal or no symptoms, and do not require any specific treatment. A high-fiber diet and fiber supplements are advisable to prevent constipation. . The American Dietetic Association recommends 20-35 grams each day. Wheat bran has much to commend it as this has been shown to reduce intra colonic pressure Ispaghula is also effective at 1-2 grams a day. Colonic stimulants should be avoided. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) says foods such as nuts, popcorn hulls, sunflower seeds, pumpkin seeds, caraway seeds, and sesame seeds have traditionally been labelled as problem foods for people with this condition. however, no scientific data exists to prove this hypothesis. The seeds in tomatoes, zucchini, cucumbers, strawberries, raspberries, and poppy seeds, are not considered harmful by the NIDDK. Treatments, like some colon cleansers, that cause hard stools, constipation, and straining, are not recommended. Some doctors also recommend avoidance of fried foods, nuts, corn, and seeds to prevent complications of diverticulosis. Whether these diet restrictions are beneficial is uncertain; Recent studies have stated that nuts and popcorn do not contribute positively or negatively to patients with diverticulosis or diverticular complications . When the spasm pain is troublesome the use of peppermint oil ( 1 drop in 50 ml water can be helpful or peppermint tablets eg colpermin. Complicated diverticulosis requires treatment of the complication. This is oftern called diverticulitis This necessitates skilled medical care of the infection, bleeding and perforation which may include intensive antibiotic treatment, intravenous fluids and surgery. Complications are more common in patients who are taking NSAIDS or aspirin . As diverticulosis occurs in an older population such complications are serious events.

5. Epidemiology
About 10% of the US population over the age of 40 and half over the age of 60 has diverticulosis. This disease is common in the US, Britain, Australia, Canada, and is uncommon in Asia and Africa . Large-mouth diverticula are associated with sclerodema