What is diverticular disease?

Diverticular disease consists of two conditions: diverticulosis and diverticulitis. Diverticulosis is the formation of several tiny pockets, or diverticula, in the lining of the bowel. Diverticula, which can range from pea-size to much larger, are formed by increased pressure from gas, waste, or liquid on weakened spots of the intestinal walls. Diverticula can form while straining during a bowel movement, as during constipation. They are most common in the lower portion of the large intestine (the sigmoid colon).

Crosscut of colon with diverticula.

Crosscut of colon with diverticula.

Complications affect about 20 percent of people with diverticulosis. One of these complications is rectal bleeding, also called diverticular bleeding. Diverticular bleeding occurs when there is chronic (long-term) injury to the small blood vessels near the diverticula.

The other complication is diverticulitis. Diverticulitis occurs when there is inflammation (swelling) and infection in one or more diverticula. This usually happens when these outpouchings become blocked with waste, allowing bacteria to build up and causing infection.

Diverticulosis is very common in Western populations and occurs in 10 percent of people over age 40 and in 50 percent of people over age 60. The rate of diverticulosis increases with age, and it affects almost everyone over age 80.

What are the symptoms of diverticulosis?

Usually diverticulosis does not cause any troublesome symptoms. Some people may feel tenderness over the affected area, or abdominal cramps.

What are the symptoms of diverticulitis?

The symptoms of diverticulitis include painful cramps or tenderness in the lower abdomen, and chills or fever.

What are the complications of diverticulitis?

Serious complications can occur as a result of diverticulitis. Most come from the development of a tear or perforation (hole) of the intestinal wall. If this happens, intestinal waste material can leak out of the intestines and into the surrounding abdominal cavity, which can cause the following problems:

  • Peritonitis (a painful infection of the abdominal cavity)
  • Abscesses ("walled off" infections in the abdomen)
  • Obstruction (blockages of the intestine)