Diverticulosis
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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.
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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, 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.
Causes
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 withough 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).
Symptoms
Often this disorder has no symptoms. The most common is bleeding (variable amounts), bloating, pain/cramping after meals or otherwise often in the Left Lower Abdomen, and changes in bowel movements (diarrhea or constipation). First time bleeding from the rectum should be followed up with a physician, especially if over age 40 because the possibility of colon cancer. Symptoms of anemia may present: fatigue, light-headedness, or shortness of breath.
Testing
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.
Complications
Infection of a diverticulum can result in diverticulitis. This occurs in 10-25% of persons with diverticulitis (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.
Infection of a diverticulum often occurs as a result of stool collecting in a diverticulum.
Treatment
Often no treatment is needed. Increases in hydration, increasing fiber content in the diet (ADA recommends 20-35 grams each day), or removing factors resulting in constipation help decrease the incidence of new diverticuli or possibly keep them from bursting or becoming inflammed (ADA website). Fiber supplements may aid if diet is inadequate. If the diverticuli are unusually large (greater than 1 inch), often infected (see diverticulitis), or exhibit uncontrollable bleeding, surgery can be performed to decrease relapse or other complications. The NIDDK says foods such as nuts, popcorn hulls, sunflower seeds, pumpkin seeds, caraway seeds, and sesame seeds should be avoided because they may irritate diverticuli. 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.
External links
- National Institude of Diabetes, Digestive and Kidney Diseases website NIH Publication No. 04–1163 dated August 2004, no e-copyright (http://www.digestive.niddk.nih.gov/ddiseases/pubs/diverticulosis/)
- Merck Manuel online (http://www.merckmanuel.com)
- J. American Diet Assoc. 2002;102:993-1000 (http://www.eatright.org)