Digestive Disorders Health Center

What is diverticulosis?

Diverticulosis is a condition that develops when pouches (diverticula ) form in the wall of the colon (large intestine ). These pouches are usually very small (5 to 10 millimeters) in diameter but can be larger.

In diverticulosis, the pouches in the colon wall do not cause symptoms. Diverticulosis may not be discovered unless symptoms occur, such as in painful diverticular disease or in diverticulitis. As many as 80 out of 100 people who have diverticulosis never get diverticulitis.¹ In many cases, diverticulosis is discovered only when tests are done to find the cause of a different medical problem or during a screening exam.

What causes diverticulosis?

The reason pouches (diverticula) form in the colon wall is not completely understood. Doctors think diverticula form when high pressure inside the colon pushes against weak spots in the colon wall.

Normally, a diet with adequate fiber (also called roughage) produces stool that is bulky and can move easily through the colon. If a diet is low in fiber, the colon must exert more pressure than usual to move small, hard stool. A low-fiber diet also can increase the time stool remains in the bowel, adding to the high pressure.

Pouches may form when the high pressure pushes against weak spots in the colon where blood vessels pass through the muscle layer of the bowel wall to supply blood to the inner wall.

What are the symptoms?

Most people don't have symptoms. You may have had diverticulosis for years by the time symptoms occur (if they do). Over time, some people get an infection in the pouches (diverticulitis). For more information, see the topic Diverticulitis.

The symptoms of painful diverticular disease are the same as those of irritable bowel syndrome (IBS), including diarrhea and cramping abdominal pain, with no fever or other sign of an infection. For information on the symptoms of IBS, see the topic Irritable Bowel Syndrome (IBS).

How is diverticulosis diagnosed?

In many cases, diverticulosis is discovered only when tests, such as a barium enema X-ray or a colonoscopy, are done to find the cause of a different medical problem or during a screening exam.

How is it treated?

The best way to treat diverticulosis is to avoid constipation. Here are some ideas:

• Include fruits, vegetables, beans, and whole grains in your diet each day. These foods are high in fiber.
• Drink plenty of fluids, enough so that your urine is light yellow or clear like water.
• Get some exercise every day. Try to do moderate activity at least 2½ hours a week. Or try to do vigorous activity at least 1¼ hours a week. It's fine to be active in blocks of 10 minutes or more throughout your day and week.
• Take a fiber supplement, such as Citrucel or Metamucil, every day if needed. Start with a small dose and very slowly increase the dose over a month or more.
• Schedule time each day for a bowel movement. Having a daily routine may help. Take your time and do not strain when having a bowel movement.