Diverticulosis and Diverticulitis

Diverticulosis and Diverticulitis Overview

What Is Diverticulosis?

Diverticulosis means having small pouches called diverticula in your intestines. These pouches can look like “pot holes” in the colon wall. Diverticula can appear anywhere in the intestines, but are most often found in the lower part of the large intestine near the anus.
How common is diverticulosis?

Diverticulosis is very common, especially in older people. It rarely happens in people under the age of 30, but it’s much more common after age 60.

What causes diverticulosis?

Doctors are not sure why diverticulosis happens. Some experts think that pressure in the colon from muscle spasms or straining may cause weak spots in the colon to form pouches in the colon wall. Diverticulosis may run in families. If someone in your family has it, you may get it too. Eating lots of fiber (like fruits, vegetables, and whole grains) might help, but this isn’t proven.

What are the symptoms of diverticulosis?

Most people with diverticulosis don’t have any problems and may not even know they have it. Others feel pain in the left lower belly, have gas, or notice a change in bowel habits, like constipation or diarrhea.

How is diverticulosis diagnosed?
Diverticulosis is generally discovered through one of the following examinations:
- Barium enema: An x-ray with liquid put into the colon through a tube.
- Colonoscopy: A thin, flexible tube with a light and camera checks the colon.
- CT scan: This x-ray test shows pictures of the inside of the body.

What are the complications of diverticulosis?
Diverticulitis happens when a pouch gets infected or inflamed. This causes belly pain, fever, low appetite, and nausea. Not everyone with diverticulosis gets diverticulitis - only 4 to 25 out of 100 people with diverticulosis ever get diverticulitis.

People with diverticulitis can develop related complications including:
- Abscess – a pocket of infected fluid outside of the colon wall
- Stricture –a narrowing of the colon.
- Fistula – a connection between the colon and another nearby organ.
- Perforation – a hole in the colon that leaks stool into the belly. This is very serious.
What is diverticular bleeding?

Diverticular bleeding happens when a blood vessel in a pouch breaks open. This causes red blood in the stool. Most people do not have pain with this bleeding. Only 3 to 15 out of 100 people with diverticulosis develop this bleeding. Usually, bleeding will stop on its own. If needed, doctors may use a camera (colonoscopy) to diagnose and treat the bleeding. Xray testing may be needed to find and treat bleeding. In rare cases, surgery may be needed to stop bleeding.

How is diverticulitis Treated?

Diverticulitis is treated with antibiotics and a light diet until you feel better. Mild cases may not need antibiotics. More serious cases with high fever, severe infection, and people with other medical problems may need hospital care and antibiotics. X-ray guided drainage (with a tube placed in the abdomen) may be needed to drain large pus collections. Surgery may be needed for patients with perforation or for people that do not improve with antibiotics.

Can diverticulosis be prevented or eliminated?

It is not known whether diverticulosis can be prevented. People who are overweight are more likely to have diverticulosis. Smoking may also increase the chance of developing diverticulosis. Once diverticula have formed, they do not go away.
Can diverticulitis be prevented?

People with diverticulosis may be told to avoid foods like popcorn, berries, nuts, and seeds. But, studies show that these foods do not actually increase the risk of diverticulitis. Eating less red meat and more fiber, staying active, and keeping a healthy weight may lower your risk of diverticulitis. Smoking and some medicines like ibuprofen and aspirin could increase the risk of diverticulitis. If you take aspirin for your heart or blood vessels, you should not stop aspirin without talking to your doctor. Opioid pain medicine and steroids may also increase the risk of diverticulitis.

Doctors have studied medications like probiotics and antibiotics to prevent diverticulitis from coming back, but none have been proven to work for sure.

Ernst Bontemps, MD and Peter M. Pardoll, MD, FACG, Center for Digestive Diseases, South Pasadena, FL – Published June 2004, Updated September 2008.

Lisa L. Strate, MD, MPH, FACG, University of Washington School of Medicine, Seattle, WA – Updated 2016

John DeBanto, MD , Glendale, CA – Updated August 2022

Ann Flynn, MD, FACG, University of Utah Health, Salt Lake City, UT - Updated April 2025.