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Understanding Diverticulosis and Diverticulitis

Many people have small pouches in the lining of the colon (the large intestine) that bulge outward through weak spots. A single pouch is called a diverticulum; multiple ones, diverticula. When you have diverticula, it is called diverticulosis.

When the pouches become inflamed, the condition is called diverticulitis. Ten to 25 percent of people with diverticulosis get diverticulitis. As many as one American in 10 over the age of 40 has diverticulosis; about half of all people over 60.

diagram of pouches that can form on the lining of the colon.
small pouches that can form on the lining of the colon.

Click to enlarge images. The small pouches that can form on the lining of the colon are called diverticula. When they are inflamed, the condition is called diverticulitis. Illustrations: Krames


Diverticulosis: Most people with diverticulosis do not have any discomfort or symptoms. However, some people may experience crampy pain or discomfort in the lower abdomen, bloating, and constipation. Irritable bowel syndrome, stomach ulcers, and other conditions cause similar symptoms, so they do not always mean a person has diverticulosis.

Diverticulitis: Diverticulitis most commonly causes abdominal pain and tenderness on the lower left side of the abdomen. Usually, the pain is sudden and severe, but it can also be mild and worsen over several days. Its intensity can change. A person may experience cramping, nausea, vomiting, fever, chills, or a change in bowel habits. Diverticulitis can lead to bleeding; infections; small tears, called perforations; or blockages in the colon. These complications always require treatment to prevent them from causing serious illness.


The leading but unproven theory is that a low-fiber diet causes diverticular disease. The disease was first noticed in the United States in the early 1900s, around the time processed foods became part of the American diet, greatly reducing fiber intake.

Fiber is the part of fruits, vegetables, and grains that the body cannot digest. Some fiber, called soluble fiber, dissolves easily in water. It takes on a soft, jelly-like texture in the intestines. You get soluble fiber from oats, barley, and fruits such as oranges and apples. Insoluble fiber passes almost unchanged through the intestines. Sources of insoluble fiber include whole wheat flour, nuts, beans, and vegetables such as carrots. Both kinds of fiber help prevent constipation by making stools soft and easy to pass.

Constipation—or hard stool—may cause people to strain during bowel movements. This may increase pressure in the colon, causing the colon lining to bulge out through weak spots in the colon wall. These bulges are diverticula.


Your healthcare provider can test for diverticular disease many ways. Because most people do not have symptoms, diverticulosis is often found through tests ordered for another problem. For example, diverticulosis is often found during a colonoscopy to screen for cancer, or polyps, or to evaluate complaints of pain or rectal bleeding.

  • Medical history. Your health professional will ask about your health and symptoms. You will be asked about your bowel habits, diet, and medications you take.
  • Blood test. This test can help detect infections.
  • Stool sample. This test may show bleeding in the digestive tract.
  • Digital rectal exam. Your healthcare provider will insert a gloved finger into your rectum to check for pain, bleeding, or a blockage.
  • Imaging tests, including CT scan, X-ray, abdominal ultrasound, or barium enema. These tests use a variety of machines and techniques to create pictures of the structures and activities inside your body.
  • Colonoscopy. Your healthcare provider will insert a small tube through your anus. A tiny video camera is in the tube and will show if there are any pouches.


Diverticulitis care focuses on clearing up the inflammation and infection, resting the colon, and preventing or minimizing complications.

Depending on the severity of symptoms, your health professional may recommend bed rest, oral antibiotics, a pain reliever, and a liquid diet. If symptoms ease after a few days, your healthcare provider will recommend gradually increasing the amount of high-fiber foods in the diet.

Severe cases of diverticulitis, with acute pain and complications, will likely require a hospital stay. Most cases of severe diverticulitis are treated with intravenous antibiotics and a few days without food or drink to help the colon rest. In some cases, surgery may be necessary.

Read More "Diverticulitis" Articles

Dealing with Diverticulitis / Understanding Diverticulosis and Diverticulitis / "Eat fresh vegetables, fruit, and whole grain products."

Winter 2010 Issue: Volume 5 Number 1 Pages 20 - 21