Diverticulitis occurs when pouches, or diverticula, in the large intestine become infected and inflamed. This may result in severe abdominal pain with or without other symptoms.

Diverticulosis is the similar sounding condition where a person develops diverticula in their large intestine. Diverticulosis affects more than 50% of people in the United States over 60 years of age.

This article discusses the signs and symptoms of both diverticulosis and diverticulitis. We also outline some potential triggers of diverticulitis, and the treatment options available.

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A lack of exercise is a possible trigger for diverticulitis.

A person may not realize they have diverticulosis until they develop diverticulitis. The symptoms of both conditions are outlined below.

Symptoms of diverticulosis

Diverticulosis does not usually cause symptoms. If symptoms do occur, they may include:

According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), less than 5% of people who have diverticulosis will go on to develop diverticulitis.

Symptoms of diverticulitis

According to the NIDDK, the most common symptom of diverticulitis is pain in the lower left abdomen. The pain typically comes on suddenly, but could also develop slowly over the course of several days.

Pain is not always the only symptom of diverticulitis. Other potential symptoms include:

People sometimes refer to inflammation or infection of the diverticula as a diverticulitis “flare-up” or “attack.”

The following factors could increase the risk of a diverticulitis attack.

  • Not getting enough exercise: Exercise helps to promote regular bowel movements. A lack of regular exercise increases the risk of constipation. This, in turn, could trigger diverticulitis.
  • Not drinking enough water: Water softens stools, allowing them to pass more easily through the colon. A person who does not drink enough water may be more prone to constipation.
  • Drinking too much alcohol: Excessive alcohol consumption could cause an imbalance in the number of good and bad bacteria in the colon. This could increase the risk of infection in the diverticula.

Doctors once thought that certain foods, such as popcorn, nuts, and seeds, could trigger diverticulitis. They, therefore, recommended avoiding these foods. However, experts now believe that restrictive diets are not necessary for people with diverticulosis or diverticulitis.

Scientists are not certain what causes diverticulitis or diverticulosis. However, they do believe that genetics and dietary factors are likely to play a role in the development of these conditions.


A 2015 review investigated the potential link between genetics and the development of diverticulosis and diverticulitis. Although the review found evidence in support of a genetic cause, the exact gene responsible remains unknown.

Dietary factors

Doctors once recommended a high fiber diet to help prevent diverticulosis and diverticulitis.

In contrast, an older 2012 study found that a diet high in dietary fiber does not help prevent diverticulosis. In fact, the study found that increased bowel movements due to high fiber intake may increase a person’s risk of developing diverticulosis.

Other risk factors

The following factors may also increase a person’s risk of developing diverticulitis:

To diagnose diverticulitis, a doctor will assess a person’s medical history and ask about their symptoms.

A doctor may also want to rule out conditions with similar symptoms. These include:

A doctor will likely also order a blood test and CT scan to look for signs of diverticulitis.

Once a doctor has diagnosed diverticulitis, they will provide treatments to help fight the infection and alleviate the pain.

In some cases, a doctor may recommend over-the-counter (OTC) pain relievers, such as acetaminophen. Doctors do not recommend NSAIDs because they are a potential risk factor for developing diverticulitis.

If OTC pain medications are not effective, a doctor may prescribe stronger pain relief.

A doctor may recommend the following treatments for mild to moderate cases of diverticulitis:

Severe cases of diverticulitis develop quickly and are more likely to cause complications. In such cases, a doctor may recommend a hospital stay, along with intravenous (IV) fluids and antibiotics.

It may also be helpful to avoid food or drink for several days, to allow the colon to rest.

Treating complications

Severe diverticulitis can cause complications, such as abscesses, perforations in the colon, and intestinal obstructions. The treatments for these conditions are outlined below.

  • Abscesses: Antibiotics are the first-line treatment for abscesses in the colon. However, if the abscess is large, or resistant to antibiotic treatment, a doctor will need to drain it.
  • Perforations: Surgery will be necessary to repair a tear or hole in the colon. If the surgeon cannot repair the perforation, they may need to remove a small section of the colon.
  • Intestinal obstruction: Sometimes, diverticulitis can cause a partial or complete blockage in the colon. A partial blockage will require surgery at some time in the future, whereas a complete blockage will require emergency surgery.

A person should see their doctor as soon as possible if they have not already received a diagnosis of diverticulosis or diverticulitis and experience symptoms of either condition.

Similarly, they should see a doctor if they have received a diagnosis of diverticulosis or diverticulitis and experience the following symptoms:

  • high fever
  • diarrhea
  • rectal bleeding
  • severe abdominal pain

Diverticulitis occurs when small pouches or diverticula in the colon become infected and inflamed. The most common symptom is pain in the lower left abdomen, sometimes with other symptoms, such as diarrhea, vomiting, or fever.

A person should see a doctor if they have a preexisting diagnosis of diverticulosis or diverticulitis and their symptoms become worse. Without the appropriate treatment, diverticulitis can cause severe complications.

A person should also see their doctor if they experience symptoms of diverticulitis for the first time. A doctor will work to diagnose the condition and provide appropriate treatments.