Diverticular disease is the general name for a common condition that causes small bulges (diverticula) or sacs to form in the wall of the large intestine (colon). Although these sacs can form anywhere in the colon, they are most common in the sigmoid colon (part of the large intestine closest to the rectum).

Diverticulosis: The presence of diverticula without associated complications or problems. The condition can lead to more serious issues including diverticulitis, perforation (the formation of holes), stricture (a narrowing of the colon that does not easily let stool pass), fistulas, and bleeding.

Diverticulitis: An inflammatory condition of the colon thought to be caused by perforation of one of the sacs. Several secondary complications can result from a diverticulitis attack. When this occurs, it is called complicated diverticulitis.

Diverticulitis Complications

  • Abscess formation and perforation of the colon with peritonitis. An abscess is a pocket of pus walled off by the body. Peritonitis is a potentially life-threatening infection that spreads freely within the abdomen, causing patients to become quite ill.
  • Rectal bleeding
  • Formation of a narrowing of the colon that prevents easy passage of stool (called a stricture)
  • Formation of a tract or tunnel to another organ or the skin (called a fistula). When a fistula forms, it most commonly connects the colon to the bladder. It may also connect the colon to the skin, uterus, vagina, or another part of the bowel.

Causes of Diverticulosis

The most commonly accepted theory ties diverticulosis to high pressure within the colon. This pressure causes weak areas of the colon wall to bulge out and form sacs. A diet low in fiber and high in red meat may also play a role. Currently, it is not well understood how these sacs become inflamed and cause diverticulitis.


Symptoms of DiverticulosisMost patients with diverticulosis have no symptoms or complications. Some patients with diverticulitis experience lower abdominal pain and a fever or they may have rectal bleeding.

Diverticulosis often causes no symptoms. It may be diagnosed during screening tests such as a colonoscopy. A CT scan of the abdomen and pelvis may be used to confirm the diagnosis of diverticulitis.

Treatment of Diverticulosis and Diverticulitis

Most people with diverticulosis have no symptoms. However, as a preventative measure, it is advised to eat a diet high in fiber, fruits, and vegetables, and to limit red meat.

Most cases of diverticulitis can be treated with antibiotics in pill form or intravenously (IV). Diverticulitis with an abscess may be treated with antibiotics with a drain placed under X-ray guidance.

Surgery for diverticular disease is indicated for the following:

  • A rupture in the colon that causes pus or stool to leak into the abdominal cavity, resulting in peritonitis, which often requires emergency surgery.
  • An abscess than cannot be effectively drained.
  • Severe cases that do not respond to maximum medical therapy including IV antibiotics and hospitalization.
  • Patients with immune system problems (e.g. related to an organ transplant or chemotherapy).
  • A colonic stricture or fistula.
  • A history of multiple attacks may result in a patient deciding to undergo surgery to prevent future attacks.