Ask the Doctors by Eve Glazier, M.D. and Elizabeth Ko, M.D

Incidence of Diverticulitis Emblematic of Unhealthy Lifestyles

Dear Doctor: I am recovering from a bout of diverticulitis. What are my chances of having another round -- and how can I avoid later episodes? Does the onset increase my risk of serious ailments such as cancer?

Dear Reader: Diverticula are sac-like protrusions from the colon wall. If you were to look inside the colon, diverticula would appear as holes within the colon wall, leading to a bulging sac coming from the intestine. In the United States, diverticula almost always occur near the end of the colon in an area called the sigmoid colon. Chronic pressure in this area from poor intestinal motility, or contractions, leads to the formation of these outcroppings. Diverticula are quite common in the Western world. In one set of screening colonoscopies -- conducted in 624 patients with an average age of 54 -- 42 percent had diverticula. Note that the likelihood of diverticula increases with age.

The presence of diverticula is known as diverticulosis. Inflammation of the diverticula is known as diverticulitis. The latter occurs when increased pressure within a diverticulum leads to a perforation through which bacteria leave the intestine, causing infection. The infection can become so severe that an abscess develops.

Diverticulitis is more prevalent among people with a low-fiber, high-fat diet that includes a lot of red meat. It is also more common among people who are obese, have little physical activity and smoke cigarettes. A common myth, and one I learned in medical school, was that nuts, seeds, corn or popcorn could become trapped in a diverticulum and lead to diverticulitis. A 2008 study not only disproved this myth, it found that the opposite was true among men ages 40 to 75.

A first-time episode of diverticulitis can mimic many of the same symptoms as colon cancer. So unless you've had a colonoscopy in the last year, you should rule out cancer by having a colonoscopy, preferably six to eight weeks after a bout of diverticulitis. One study found that 2.8 percent of people who had a follow-up colonoscopy were then diagnosed with colon cancer. This rate rises for those who have had an abscess related to diverticulitis.

After the first attack of diverticulitis, the likelihood of a second attack is about 33 percent; the likelihood of a third bout after a second bout is also about 33 percent. To help prevent another attack, you need to get the gut moving. That is, increase fiber in your diet. If you can't do this simply by increasing your consumption of high-fiber vegetables, fruits and nuts, then a fiber supplement is in order.

Exercising also will decrease the risk of another attack of diverticulitis. Because diverticulitis occurs more frequently in obese people, losing weight may also decrease your chance of another attack. Decreasing the amount of red meat and fat in your diet may lessen your chances as well.

Nationwide, the incidence of diverticulitis is increasing, especially in people ages 18 to 44. Some of the increase could be attributed to better diagnosis, but the rise is also emblematic of our unhealthy diet and sedentary lifestyle.

(Send your questions to, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)