Diverticulosis is a condition in which small pouches, called diverticula, protrude from the intestinal wall. Most of the time diverticulosis is of little consequence; but in 10 percent to 25 percent of cases, one or more of these pouches will become inflamed or infected, a condition called diverticulitis. Diverticulosis and diverticulitis typically affect the colon -- most often the sigmoid colon, an S-shaped segment located in the lower left portion of the abdomen.

Diverticulosis is a common condition estimated to affect 35 percent to 50 percent of Americans. Its incidence increases with age, probably due to weakening of the intestinal walls over time. In the United States, diverticulosis affects an estimated 10 percent of those over 40 years old and nearly 50 percent of those between 60 and 80 years of age. By age 80, most Americans will have developed diverticulosis.

Elevated pressure within the colon is thought to be a factor in promoting formation of diverticula. Pressure can be raised by eating a low-fiber diet, which produces small, hard stools that require relatively high pressure to evacuate. Evidence of diet's role is that diverticular disease is common in industrialized countries, including the United States, in which low-fiber diets are common. Conversely, in areas where high-fiber diets are consumed, such as many Asian and African countries, diverticular disease is uncommon.

Patients with diverticulosis may be symptom-free, or they may notice mild, intermittent, nonspecific symptoms such as abdominal tenderness, bloating or cramping. As in your mother's case, it is common for the condition to be detected only after a procedure is performed for another reason. On rare occasions, blood vessels within diverticula may rupture, causing bleeding from the rectum.

Often this bleeding is inconsequential and will stop on its own, but it is a sign that warrants consultation with a physician. In some instances, bleeding may require surgical intervention, or it may be an indication of another underlying problem.

Diverticulosis itself does not require medical treatment, but a healthy diet that includes adequate fiber and fluids should be maintained. Fiber and fluids prevent constipation and high pressure in the colon by making the stool bulkier, softer and easier to pass. Although a high-fiber diet does not reverse diverticulosis, it can help reduce symptoms, prevent formation of additional diverticula and inhibit development of diverticulitis.

According to the American Dietetic Association, a healthy diet should include 20 to 35 grams of fiber per day. Foods such as whole-grain breads and cereals, fruits, vegetables and beans are all sources of dietary fiber. It can be difficult to convince asymptomatic individuals to change their diet, and some physicians may recommend taking a fiber supplement to assure consumption of adequate dietary fiber.

Some physicians advise patients with diverticulosis to avoid eating nuts or foods containing small seeds, such as strawberries, raspberries and tomatoes; although there is no evidence to suggest that the recommendation has any effect on the condition.

Although most people tolerate diverticulosis without a problem, diverticulitis can begin when waste becomes trapped within a diverticulum, causing inflammation and distention of the diverticulum, and creating an environment that promotes overgrowth of the bacteria that normally live in the colon.