What is diverticulitis?

Diverticular disease, also called diverticulosis, is an infection in the tiny pouches that some people get in their colon.

The pouches are called diverticula and can sometimes bulge out through weak spots in your colon. The pouches can become inflamed (red, swollen) or infected.

Diverticulitis is when these tiny pouches in the colon get infected. About half of all Americans over age 60 will have diverticulosis; some people with diverticulosis can also get diverticulitis.

Diverticular disease is often seen in developed countries and is very common in the U.S., England and Australia; people in these countries eat less fiber.

Diverticular disease is rare in countries such as Asia and Africa, because people in these countries eat more fiber and vegetables.

What causes diverticular disease?

The cause of diverticular disease is unknown, but physicians think it might happen when not enough fiber is eaten.

Fiber is the part of fruits, vegetables and grains that the body cannot digest and helps make your stools soft and easy to pass. Eating more fiber helps stop constipation, which is the main cause of greater pressure in your colon.

When you are constipated, your muscles strain to move stool that’s too hard. The extra pressure from this straining makes the weak spots in your colon bulge out; these pouches that bulge out are the diverticula.

It is unknown what causes the infection that leads to diverticulitis, but it’s thought that it may start when stool or bacteria are caught in the diverticula.

Diverticular disease symptoms

Each person’s diverticular disease symptoms may vary and may include:

You can have diverticulosis and not have any pain or symptoms, however, diverticulosis symptoms may include mild cramps, swelling, or bloating and constipation.

These symptoms of diverticulosis can also be caused by irritable bowel syndrome (IBS), stomach ulcers or other health problems.

However, it does not always mean that you have diverticulosis.

The most common diverticulitis symptom is abdominal pain. The most common sign that you have it is feeling sore or sensitive on the left side of your lower belly.

If an infection is the cause of diverticulitis, then you may have fever, nausea, vomiting, chills, cramping and constipation.

Diverticular colitis
This is when the colon gets inflamed as a result of the diverticular disease.

Diverticular colitis is less common than diverticulitis.

The symptoms of diverticular disease may look like other health problems; always see your physician to be sure.

How is diverticular disease diagnosed?


Your physician will look at your past health and do a physical exam. He or she may also use some of the following tests to diagnose diverticular disease:

Barium enema or lower GI (gastrointestinal) series

An X-ray exam of your rectum, the large intestine and the lower part of your small intestine.

You will be given a metallic fluid called barium that coats the organs so that they can be seen on an X-ray.

The barium is put into a tube and inserted into your rectum as an enema.

An X-ray of your belly will show if you have any narrowed areas, blockages or other problems


Looks at the full-length of your large intestine and can help check for any abnormal growths, tissue that is red or swollen, ulcers or bleeding.

A long, flexible, lighted tube is put into your rectum up into the colon allowing your physician to see the lining of your colon and take out a tissue sample to test it. Your physician can also treat some problems that may be found.

Learn more about colonoscopies

CT scan

Shows detailed images of any part of the body, such as the bones, muscles, fat and organs and is used to check for complications of diverticular disease like diverticulitis.

Digital rectal exam

Checks if you have problems in the anus or rectal area.

Your physician will gently put a gloved, lubricated finger into your rectum to check the muscle that closes off the anus

Flexible sigmoidoscopy

A test that checks the inside of part of your large intestine and helps to tell what is causing constipation.

A short, flexible, lighted tube is put into your intestine through the rectum blowing air into your intestine to make it swell, making it easier to see the inside. A tissue sample can be taken if needed.

Stool sample

Checks for any abnormal bacteria or parasites in your digestive tract. A small stool sample is taken and sent to a lab.

Virtual colonoscopy

A CT scan that checks your colon using air and contrast.

How is diverticular disease treated?

In many cases, diverticulitis symptoms can be relieved through diet and lifestyle changes, such as eating whole grains, fruit, vegetables and beans. Experts suggest eating 20 to 35 grams of fiber each day.

Diverticulitis treatment also includes medication.

Diverticulitis treatment plans will be determined by a patient's care team based on age, medical history, type of diverticulitis symptoms and personal preferences.