Diverticulosis and diverticulitis

Diverticula are pouch-like structures that form in the wall of the large intestine. When the large intestine contains diverticula, the condition is called diverticulosis. It is usually harmless and causes no problems. When these pouches bleed or become inflamed or infected, the condition is called diverticulitis. Diverticulitis can cause a variety of symptoms, from abdominal pain and cramping to fever.

Most diverticulitis-related infections are small and heal on their own. But they can also lead to an abscess on the bowel wall. An abscess is a collection of pus surrounded by inflamed and swollen tissue. It can destroy surrounding tissue and create a tunnel-like connection between the intestine and skin, or between two organs in the digestive tract. Such a connection is called a fistula.

Other possible complications of diverticulitis include obstruction of the intestine due to scarring, and breaking open of a diverticulum. A rare but life-threatening complication called peritonitis can occur when one or more diverticula break open, leaking infection-causing microbes into the abdominal cavity.

Symptoms of diverticulitisf393c9c7-0719-4526-9dbb-f0f1c60b10941620726702697

Diverticulitis nearly always causes:

  • abdominal pain
  • tenderness to pressure in the lower abdomen

It can also cause:

  • fever
  • nausea
  • vomiting
  • chills
  • cramping
  • constipation, diarrhea, or other change in bowel habits
  • rectal bleeding
  • sharp pain with breathing or jarring movements such as walking

Diagnosing diverticulitis

The symptoms of diverticular disease can mimic other diseases. These include irritable bowel syndrome, stomach ulcers, appendicitis, and Crohn's disease.

Your doctor will ask about your medical history, bowel habits, and diet. He or she will perform a physical examination. This will include a rectal examination with a gloved finger to detect tenderness, blockage, or blood in the rectum or colon. Your doctor may press on your abdomen to check for tenderness.

Tests that may help diverticulitis include:

  • blood tests for signs of infection
  • a test to check for blood in the stool
  • X-ray, computed tomography (CT) scan or ultrasound to look for diverticulitis or abscesses inside the colon

Treating diverticulitis

Mild diverticulitis can often be treated by self-help steps with or without medication. Some people need surgery.

Self care

Increasing the amount of fiber in the diet can help prevent painful flare-ups of diverticulitis or bleeding. Try to get 20 grams to 35 grams of fiber a day. The best sources are fruits, vegetables, and grains. Your doctor also may recommend unprocessed bran or a fiber supplement. If you plan to increase your fiber intake, do it gradually and be sure to drink plenty of water to prevent constipation.

Being physically active may help keep diverticulitis in check.

People with diverticulosis or diverticulitis were once advised to eliminate from their diets hard-to-digest foods such as nuts, corn, popcorn, and seeds. Why? The thinking was that these foods would get stuck in the diverticula and cause inflammation. But there is no evidence to back up this recommendation, and nuts and seeds are high-fiber foods, which are good for people with diverticular disease.

If you have not had a colonoscopy recently, your doctor may recommend that you have one. This is because the symptoms of colon cancer can sometimes mimic diverticulitis.


Antibiotics are often used to treat diverticulitis. These can usually be taken as pills at home. If you have severe pain or an infection, though, you may need to be treated in a hospital so antibiotics can be given intravenously (into a vein). Moderate-to-severe diverticulitis may require bed rest and a liquid diet to help the large intestine recover.


If you have an abscess, drainage or surgery may be needed to clean out the infection. The choice depends on the extent of the problem and your overall health.

Emergency surgery is required to treat peritonitis. Surgery also may be needed to treat a particularly severe episode of diverticulitis or complications such as continuous bleeding, perforation of an abscess, a fistula, or obstruction of the large intestine.

The most common surgical procedure for diverticulitis is resection of the large intestine. It involves removing the part of the colon that contains diverticula and reattaching the otherwise healthy ends.


As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles.

No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.

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