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by Wood D
(Acute Diverticulitis; Acute Colonic Diverticulitis)


Small pouches can form in the wall of the large intestine. Diverticulitis is an infection or swelling in this pouch.

Infected pouches along the colon.
Copyright © Nucleus Medical Media, Inc.


Digested food or stool can become trapped in one of the pouches. This leads to swelling and infection.

It is not clear why these pouches form. It may be caused by extra pressure from slow moving food. The food can cause increased pressure on the walls of the bowel. The wall gives way as a pouch.

Risk Factors

It is more common in people who are older than 50 years of age.

Factors that may increase your chance of getting diverticulitis include:

  • Eating a low-fiber diet—fiber softens stools and makes them pass through the bowel more easily
  • Straining to pass a hard stool—causes increased pressure in the bowel
  • Previous episodes of diverticulitis
  • High-meat diet or high-protein diet
  • Defects in the colon wall
  • Chronic constipation
  • Smoking
  • Obesity


Symptoms can come on suddenly. They vary person to person and even by flare up in same person.

Symptoms may include:

  • Abdominal pain
  • Tenderness—usually in the lower left part of the abdomen
  • Swollen and hard abdomen
  • Fever
  • Chills
  • Poor appetite
  • Nausea and vomiting
  • Diarrhea and/or constipation
  • Cramping
  • Rectal bleeding


You will be asked about your symptoms and health history. A physical and rectal exam will be done. An early diagnosis is important.

The doctor may suspect diverticulitis based on your exam. Other tests may be done to rule out other conditions with similar symptoms. Tests may include:

Other tests may be done to examine the colon. The tests may only be done after the inflammation is treated. Test options include:


Left untreated, the pouch can break and release stool into the belly. This is a medical emergency. It will require surgery.

The goals of treatment are to:

  • Resolve the infection and inflammation
  • Rest the bowel
  • Prevent complications

Treatments include:


Antibiotics are given to fight any infection. Pain medicine can help to manage the abdominal pain.

You may also be given medicine to help control vomiting.

Diet and Fluids

The bowel will need some time to rest. A clear liquid diet will be needed for the first 2-3 days. This should help decrease symptoms.

A hospital stay may be needed if you have severe symptoms. An IV will deliver fluid and nutrition into your bloodstream. This will allow your bowel to have full rest.

Preventive Care

Having one attack increases your chance of another. Changes in your diet can help prevent future attacks.

  • Increase the amount of fiber you eat. Eat more fruits, vegetables, and whole grains.
  • Supplement your diet with a fiber product. Talk to your doctor about recommendations.
  • Avoid laxatives and enemas
  • Avoid opioid medications. They can slow down bowel movement and can cause constipation.


Surgery to remove the section of the bowel with pouches may be advised if:

  • You have had many attacks during a 2 year period.
  • A pouch breaks and the contents spread into the belly. The contents will need to be cleaned out of the belly.

Surgery is also used to treat complications of diverticulitis such as:

  • Abscess—the pouch fills with pus
  • Blocked bowel—scar tissue blocks movement of stool
  • Fistula—colon tissue attaches to another organ, such as the bladder, the uterus, or the vagina

The diseased part of the bowel will be removed. The normal parts of the bowel will then be connected back together.

An emergency surgery will need additional steps. The diseased part will be removed. The healthy ends cannot be reconnected right away. Your bowel will need time to rest and heal. The upper part of the bowel will be attached to the abdominal wall. A stoma will allow waste to pass from the intestine to a bag outside of your body. If possible, the healthy bowel will be reconnected after 6-12 weeks.


A healthy bowel may help prevent diverticulitis. To keep stool moving through the colon and decrease the risk of constipation:

  • Eat a balanced, high-fiber diet. Include plenty of fruits, vegetables, and whole grains.
  • Drink plenty of water each day.
  • Exercise regularly.


American Society of Colon and Rectal Surgeons  https://www.fascrs.org 

National Institute of Diabetes and Digestive and Kidney Diseases  https//www.niddk.nih.gov 


Dietitians of Canada  http://www.dietitians.ca 

Health Canada  https://www.canada.ca 


Diverticular disease. American Society of Colon and Rectal Surgeons website. Available at: https://www.fascrs.org/patients/disease-condition/diverticular-disease. Updated October 2012. Accessed October 2, 2017.

Diverticular disease. National Institute of Diabetes and Digestive and Kidney Diseases website. Available at: https://www.niddk.nih.gov/health-information/digestive-diseases/diverticulosis-diverticulitis. Accessed October 2, 2017.

Diverticulitis. EBSCO DynaMed Plus website. Available at:  https://www.dynamed.com/topics/dmp~AN~T113975/Diverticulitis  . Updated December 21, 2015. Accessed October 2, 2017.

2/9/2012 DynaMed Plus Systematic Literature Surveillance  https://www.dynamed.com/topics/dmp~AN~T113975/Diverticulitis  : Hjern F, Wolk A, Håkansson N. Smoking and the risk of diverticular disease in women. Br J Surg. 2011;98(7):997-1002.

7/31/2018 DynaMed Plus Systematic Literature Surveillance  https://www.dynamed.com/topics/dmp~AN~T113975/Diverticulitis  : Ma W, Jovani M, et al. Association between obesity and weight change and risk of diverticulitis in women. Gastroenterology. 2018 Jul;155(1):58-66.e4.

Revision Information

  • Reviewer: EBSCO Medical Review Board Daus Mahnke, MD
  • Review Date: 09/2018
  • Update Date: 07/17/2018