Diverticulosis and diverticulitis.

Diverticulosis is a condition in which outpouchings form in the walls of the intestines. These pouches, known as diverticula, are about the size of large peas. They form in weakened areas of the bowels, most often in the lower part of the colon (large bowel). (See figure 1.)

What Are the Symptoms of Diverticulosis?

Most people with diverticula do not have any symptoms from them. They may never know they have the condition. Some people feel tenderness over the affected area or muscle spasms in the abdomen. Pain may be felt on the lower left side of the abdomen or, less often, in the middle or on the right side.

Although the diverticula themselves do not cause symptoms, complications such as bleeding and infection may occur. Bleeding is an uncommon symptom and is usually not severe. Sometimes the pouches become infected and inflamed, a more serious condition known as diverticulitis. (See figure 2.) When inflammation is present, there may be fever and an increased white blood cell count, as well as acute abdominal pain. Diverticulitis also may result in large abscesses (infected areas of pus), bowel blockage, or breaks and leaks through the bowel wall.

How Are These Disorders Diagnosed?

Often diverticulosis is unsuspected and is discovered by an x-ray or intestinal examination done for an unrelated reason. The doctor may see the diverticula through a flexible tube (colonoscope) that is inserted through the anus. Through this scope, the diverticula may be seen as dark passages leading out of the normal colon wall. The doctor also may do a barium enema, an x-ray that reveals the outpouchings in the walls of the colon.

If rectal bleeding occurs, the doctor may take a special x-ray (angiography). In this procedure, dye is injected into an artery that goes to the colon, so that the site of the bleeding problem can be located. Diverticulitis may be diagnosed when a patient has pain and tenderness in the lower abdomen with disturbed bowel function and fever.

How Common Are These Disorders?

Diverticulosis is very common, especially in older people. Studies show that about 10 percent of people over the age of 40 and nearly half of people over age 60 have diverticulosis. But among those who are found to have diverticula, only about 20 percent develop diverticulitis, and of those, only a small number have very serious or life-threatening complications.

What Causes Diverticula To Form?

No one knows for sure why the pouches form. Scientists think they may be caused by increased pressure inside the colon due to muscle spasms or straining. The sacs might form when increased pressure acts on soft spots along the bowel wall, especially if the person has constipation problems or uses laxatives too often.

How Serious Are These Disorders?

For most people, diverticulosis is not a problem. Diverticulitis, on the other hand, is a problem, sometimes a serious one. (See figure 2.) For instance, when one of the sacs (a diverticulum) becomes infected and inflamed, bacteria enter small tears in the surface of the bowel. This leads to small abscesses. Such an infection may remain localized and go away within a few days. In rare cases, the infection spreads and breaks through the wall of the colon causing peritonitis (infection of the abdominal cavity) or abscesses in the abdomen. Such infections are very serious and can lead to death unless treated without delay.

What Are the Treatments?

If you have diverticulosis with no symptoms, no treatment is needed. Some doctors advise eating a high-fiber diet and avoiding certain foods. Laxatives and enemas should not be used regularly. Patients with diverticulitis may be hospitalized and treated with bed rest, pain relievers, antibiotics, fluids given by vein, and careful monitoring.

Is Surgery Ever Necessary?

The majority of patients will recover from diverticulitis without surgery. Sometimes patients need surgery to drain an abscess that has resulted from a ruptured diverticulum and to remove that portion of the colon. Surgery is reserved for patients with very severe or multiple attacks. In those cases, the involved segment of colon can be removed and the colon rejoined.

In some cases, the two ends of the colon cannot be rejoined right away, so more than one operation is needed. For instance, an operation may be performed to drain an abscess and remove diseased colon and a second operation done to rejoin the colon. In this case, the surgeon must connect the colon to a surgically created hole on the body's surface (colostomy) until a second operation can be done to reconnect the colon.

The delay between operations may be only a few weeks, or it might be several months if the patient needs time to overcome infection and build up strength. In rare cases, three operations are needed: the first to drain an abscess, the second to remove part of the colon, and the third to rejoin the bowel.

What About Diet?

If you have diverticulosis with no symptoms, you don't need treatment, but it is a good idea to watch your diet. The diet some doctors recommend is the same kind that is healthy for most people--eat more foods high in fiber. (See Diet, Nutrition & Cancer Prevention: The Good News in the additional readings section.) A fiber-rich diet helps prevent constipation and promotes a healthy digestive tract. Fiber-rich foods include whole-grain cereals and breads, fruits, and vegetables. A fiber-rich diet is also thought to help prevent diverticula from forming.

Remember, diverticula usually cause no problems at all, so a diagnosis of diverticulosis should not be a serious concern.

Additional Readings

Diet, Nutrition & Cancer Prevention: The Good News (NIH Publication No. 87-2878). Pamphlet available from the Cancer Information Service, Office of Cancer Communications, National Cancer Institute, 9000 Rockville Pike, Bethesda, MD 20892. 1-800-4-CANCER. Discusses high-fiber diet and fiber-rich foods.

Diverticulitis and Diverticulosis. Fact sheets available from the National Organization for Rare Disorders, Inc., P.O. Box 8923, New Fairfield, CT 06812-1783. [phone].

Ertan A. Colonic diverticulitis: recognizing and managing its presentations and complications. Post-graduate Medicine 1990; 88(3): 67-72, 77. This article for primary care physicians discusses how to recognize, evaluate, and manage diverticulitis.

Larson DE, Editor-in-chief Mayo Clinic Family Health Book. New York: William Morrow and Company, Inc., 1990. General medical guide with section on diverticular disease. Available in libraries and bookstores.

Weck E. New hope for those with diverticular disease. FDA Consumer 1987; 21(6): 23-5. Article reprint available from the Food and Drug Administration, 5600 Fishers Lane, Rockville, MD 20857 or in libraries.

National Digestive Diseases Information Clearinghouse 

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