Diverticulosis and Diverticulitis

What is Diverticulosis?

The term diverticulosis refers to the presence of small pockets, or diverticula in the large intestine. This is a common finding in persons over the age of 40, and in most people, it is an incidental finding which causes no symptoms at all. A diverticulum forms as the result of pressure generated when muscular contractions occur in the colon. There are openings in the muscular wall of the colon where small arteries pass through to provide circulation to the inner lining of the colon. These openings gradually enlarge and the mucosa or lining of the colon bulges through. This creates a thin walled pocket consisting only of the mucosa and the outer membrane over the colon called the serosa.
Diverticulosis is also associated with spasm, usually in the sigmoid colon. This may cause cramping and pain, and can be result in constipation or diarrhea. Extreme thickening of the muscle layer of the colon may occur, and can cause symptoms suggestive of obstruction or blockage.

Formation of a diverticulum

Diverticula are usually found in the sigmoid colon


A small perforation of the diverticulum results in leakage of stool into the space beneath the serosal membrane and formation of an abscess around the colon. Symptoms are pain in the left lower abdomen, fever, and pain with passage of bowel movements. Obstruction of the colon may occur due to spasm and swelling of the colon. The severe inflammation may even lead to peritonitis. Many patients will respond to oral antibiotics, but this can be a serious illness requiring hospitalization and even major surgery, especially if complications such as an abscess or perforation occur.

Recurrent Diverticulitis

Diverticulitis can be a recurrent problem. Prompt treatment may avert more serious complications. In our patients who have had diverticulitis in the past, we ask that you call our office if you think you are having another attack. Our usual response is to begin antibiotics and see you in the office in a few days to make sure the attack is resolving.


Bleeding from diverticulosis is the result of rupture of a small artery associated with the diverticulum. This bleeding is often massive and is a serious medical emergency. Transfusions, intensive care, emergency colonoscopy, bleeding scans, and arteriograms may be required to manage this problem. If bleeding cannot be controlled, emergency surgery is sometimes the only solution. This usually requires removal of most of the colon in order to control the bleeding.
Passage of small amounts of blood should not be attributed to diverticulosis. This is more often due to hemorrhoids, fissures, polyps, or colon cancer. Medical attention should be sought for rectal bleeding, or for any change in the bowel habit. Periodic examination of the stool for occult blood (Hemoccult test) is also advisable as colon cancer and diverticulosis may coexist and cause similar symptoms. X-rays such as barium enemas may be difficult to interpret in the presence of diverticulosis, and a cancer can be easily missed.

Diet and Treatment

A diet high in fiber will often help to normalize the bowel habit and alleviate pain as well. Fresh fruits, vegetables and bran are all excellent sources of dietary fiber. Bulk laxatives containing psyllium or methylcellulose may also be helpful, especially if constipation is present. A gradual increase in dietary fiber over a period of a few weeks is best tolerated. Abrupt increases in dietary fiber may cause bloating and excessive gas. Mild sedatives and antispasmodics are used if fiber alone does not control symptoms.

It is thought that diverticulitis may occur due to blockage of the mouth of the diverticulum by hard stool or by indigestible roughage. These food particles may cause pain or a blockage as they pass through an area of the colon which has been narrowed by diverticulitis or severe spasm associated with diverticulosis. If foods such as nuts, corn, popcorn and seeds cause lower abdominal pain or cramping, one should avoid them. Unfortunately, no dietary therapy has been shown to be effective in preventing complications of diverticulosis. We do recommend avoiding nuts and seeds if you have had diverticulitis or diverticular bleeding in the past.