Diverticulosis, otherwise known as "diverticular disease", is the condition of having diverticula in the colon which are outpocketings 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. more...
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, England, Australia, Canada, and is uncommon in Asia and Africa. It is the most common cause for bleeding in US adults over the age of 40 years.
Diverticuli are thought to be caused by increased pressure within the lumen of the colon. Constipation is the most common cause of diverticulosis. Increased intra-colonic pressure secondary to the constipation leads to weaknesses in the colon walls giving way to diverticula. Other causes may include a colonic spasm which increases pressure, which may be due to dehydration or low-fiber diets (merck manual online 2005); although this may also be due to constipation. Fiber causes stools to retain more water and become easier to pass (either soluble or insoluble fiber will do this). A diet without sufficient fiber makes the stools small, requiring the bowel to squeeze harder to remove the smaller stool. Summarizing the risk factors from this and the introduction: low-fiber/high-fat diet, increasing age, constipating conditions, and connective tissue disorders which may cause weakness in the colon wall (ex. Marfan syndrome).
Often this disorder has no symptoms. The most common is bleeding (variable amounts), bloating, abdominal pain/cramping after meals or otherwise often in the left lower abdomen, and changes in bowel movements (diarrhea or constipation). Sometimes, symptoms include unspecific chronic discomfort in the lower left abdomen, with occasional acute episodes of sharper pain. The discomfort is sometimes described as a general feeling of pressure in the region, or pulling sensation. A tickling sensation may be felt as the small pockets fill and unfill; a feeling like gas may be moving in areas outside the colon. First-time bleeding from the rectum should be followed up with a physician, especially if over age 40 because of the possibility of colon cancer. Symptoms of anemia may present: fatigue, light-headedness, or shortness of breath.
Colonoscopy is the most used test for diagnosis. This is important for treatment and investigation of other diseases. Other tests in include abdominal X-ray, barium enema, CT, or MRI.
Infection of a diverticulum can result in diverticulitis. This occurs in 10-25% of persons with diverticulosis (NIDDK website). Tears in the colon leading to bleeding or perforations may occur, intestinal obstruction may occur (constipation or diarrhea does not rule this possibility out), peritonitis, abscess formation, retroperitoneal fibrosis, sepsis, and fistula formation.
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