Understanding Diverticulitis: Causes and Treatment

Medically Reviewed by Minesh Khatri, MD on February 21, 2023
4 min read

Aging and heredity are primary factors in the development of diverticulosis and diverticulitis, but what you eat also plays a role. Eating a diet low in fiber and high in refined foods may increase the risk. Indeed, in Western societies, an estimated 10% of people over 40 develop diverticulosis; the figure reaches at least 50% in people over 60. Diverticulitis will occur in about 10%-25% of those with diverticulosis.

Though it hasn't been proven, some researchers think that if you are often constipated and usually strain when you have a bowel movement, you may create enough pressure in the intestinal walls to weaken them and begin the development of diverticular pouches. Another school of thought is that not enough fiber in the diet is responsible. The lack of fiber leads to increased bowel wall strain to move stool through the colon. That then causes increased local pressures that lead to the formation of pouches at weak points in the colon wall. The increased pressure along with undigested food caught in these pouches can erode the diverticular wall, causing inflammation and possible bacterial infection, which can result in diverticulitis.

Most doctors don’t notice cases of diverticulosis until they screen for other conditions. For instance, the pouches might show up in a colonoscopy or an X-ray.

Your doctor might take these steps to know for sure:

Gather your medical history. They’ll ask you about your diet, general health, meds you take, and how often you have bowel movements.

Do a physical exam. This may include a digital rectal exam. With a lubricated gloved finger, they’ll gently check your anus for bleeding, pain, or other signs.

Perform tests. These might include:

  • A CT scan makes images of your digestive tract.
  • A colonoscopy looks in your rectum and colon.
  • A blood sample shows if you have signs like anemia or inflammation.
  • A lower GI series uses X-rays to get a better look at your large intestine.

Once you develop diverticula, they are there to stay unless you have them surgically removed, which is not usually done. You can minimize the chances of developing an infection by modifying your diet. If you have a mild case of diverticulosis, your doctor may have you eat a high-fiber diet to make sure the bowels move regularly and to reduce the odds of getting diverticulitis.

If you develop diverticulitis you need to see a doctor to make sure you recover completely and to avoid possible life-threatening complications. Diverticulitis is treated using diet modifications, antibiotics, and possibly surgery.

Mild diverticulitis infection may be treated with bed rest, stool softeners, a liquid diet, antibiotics to fight the infection, and possibly antispasmodic drugs.

However, if you have had a perforation or develop a more severe infection, you will probably be hospitalized so you can receive intravenous (through a vein) antibiotics. You may also be fed intravenously to give the colon time to recuperate. In addition, your doctor may want to drain infected abscesses and give the intestinal tract a rest by performing a temporary colostomy. A colostomy creates an opening (called a stoma) so your intestine will empty into a bag that is attached to the front of the abdomen. Depending on the success of recovery, this procedure may be reversed during a second operation.

If you have several attacks of acute diverticulitis, your doctor may want to remove the affected section of the intestine when you are free of symptoms. You may also need surgery if intravenous therapy does not effectively treat an acute attack of diverticulitis. Whatever the treatment, the chances for a full recovery are very good if you receive prompt medical attention.


High-fiber diet or fiber supplements. This will depend on how much your doctor thinks fiber (or the lack of it) might play into your condition. Fiber-rich foods reduce gas and pain in your stomach.

They might suggest a fiber product like Citrucel or Metamucil. They come in pill, powder or wafer forms. You’ll take it with lots of water.

Probiotics. Research is still being done on how probiotics -- live bacteria that live in your stomach and intestines -- can help fight diverticulosis symptoms. Yogurt and supplements are good sources.

It’s important to check with your doctor before taking supplements of any kind.

What about nuts and seeds?

In the past, doctors thought you had to avoid certain foods if you had diverticulosis. These included nuts, seeds like sunflower and sesame, and even little seeds in fruits and vegetables such as cucumbers and strawberries. But recent research shows these foods don’t harm people with diverticulosis.

You should drink at least eight 8-ounce glasses of water daily to prevent constipation. If you do become constipated, prunes or prune juice may serve as natural laxatives. Follow a low-fat diet; fat slows down the passage of food through the intestine.

During acute attacks of diverticulitis, stick to clear liquids or broths while diverticula are inflamed and sensitive.