Diverticulosis and Diverticulitis

Note: Many disorders can affect the digestive tract. Some can have symptoms that may be similar to or overlap with gastrointestinal (GI) functional or motility disorders. These will have uniquely identifying features which differentiate them from functional GI or motility disorders.

What is Diverticulosis and Diverticulitis?

Diverticulosis: Diverticulosis is the condition of having small pouches protruding from the wall of the colon. These pouches are extremely common among Americans, for example, where about 1 out of 10 people over age 40, half of those older than 60, and 2 out of 3 over age 80 have them.

Diverticulosis itself is really not a problem, as the pouches themselves are harmless and rarely cause symptoms. However, the situation becomes more serious if the pouches become infected from, for example, stool getting trapped in the pouch.

Diverticulitis: If infection occurs, the condition is called diverticulitis. Diverticulitis is more serious because infection can lead to other problems. Diverticulosis leads to diverticulitis in about 1 out of 5 to 1 out of 7 cases.

Read more about the difference between Diverticula, Diverticulosis, and Diverticulitis

Researchers think a diet low in fiber is to blame for a high incidence of diverticulosis. Fiber is important because it helps keep stool soft and bulky so it can pass easily through the colon. Without enough fiber stool becomes hard, which creates pressure in the colon as the muscles strain to move the stool. This pressure is what causes the parts of the wall of the colon to pop out into pouches.



Most people with diverticulosis don’t know they have it unless they have studies of the colon done for other reasons and the doctor notices the pouches. But some people do have signs like mild cramps, bloating, or constipation.

People whose diverticulosis develops into diverticulitis have symptoms of abdominal pain (usually in the lower left side), fever, nausea, vomiting, diarrhea or constipation, and chills. Symptoms of diverticulosis and diverticulitis are similar to other conditions, such as appendicitis, ovarian cyst, peptic ulcer, Crohn’s disease, and irritable bowel syndrome – so the doctor may do tests such as x-rays, ultrasound, or endoscopy to make the right diagnosis.


The best way to help prevent diverticulitis is to keep diverticulosis under control. That means eating a high fiber diet – which requires 20 to 35 grams of fiber each day. Fiber is found in grains, vegetables, and fruits. Also, it is important to drink enough fluids – at least eight glasses – throughout the day to help keep stool soft.

Learn more about nuts, seeds, and diverticula


Prompt treatment for diverticulitis is important because infection can cause complications like abscess (an infected area that can destroy tissue); perforation of the colon, which can let the infection leak out into the abdominal cavity; and peritonitis, an infection in the abdominal cavity that can be very serious and requires immediate medical attention. Treatment usually involves two steps: antibiotics to clear up the infection, and diet restrictions while the colon heals.


The doctor usually prescribes a 7 to 10-day course of antibiotics, and the doctor’s office will probably check with you daily to make sure the infection is not getting worse (if it is, you may need to check into the hospital for more aggressive antibiotic treatment).

Diet therapy

Until the colon heals, you’ll need to be on a liquid diet (water, broth, Jell-O, etc.) or a low fiber diet. After the infection is gone, the doctor will want you to switch to a high fiber diet. The new diet will not get rid of existing pouches in the colon, but the bulk from the extra fiber will help the stool move through your system better, which in turn decreases pressure and helps prevent the development of more pouches and protect against future infection.

Other medications

Pain relievers and medicines to control intestinal cramping may also be prescribed.

People with serious infection, as well as the elderly and those who are immunocompromised or taking corticosteroids, may have to be hospitalized to receive intravenous antibiotics and fluids. Surgery to remove part of the colon may be necessary for people who have frequent infections or who develop severe complications like abscess or perforation of the colon.

Adapted from “Diverticula, Diverticulosis, Diverticulitis: What’s the Difference?” IFFGD Publication #169 by W. Grant Thompson, MD, FRCPC, Emeritus Professor of Medicine, University of Ottawa, Ontario, Canada.

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