How to Say It: peh-rit-oh-NYE-tis


Peritonitis is inflammation of the peritoneum. This is the thin tissue that covers the inside of the abdomen. It also covers the outside of the intestines and other abdominal organs.

There are three types:

  • Primary
  • Secondary
  • Dialysis-related

This health problem needs care right away. It can be deadly.


This health problem is caused by infection. Common causes are:

  • Primary—fluid builds up in the belly and becomes infected due to health problems, such as cirrhosis of the liver.
  • Secondary—bacteria enters the belly due to an injury or a health problem, such as a ruptured appendix.
  • Dialysis-related—bacteria enters the peritoneal cavity during or after peritoneal dialysis to treat kidney disease

Secondary Peritonitis

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Risk Factors

Things that may raise the risk of this problem are:


Problems may be:

  • Belly pain that is worse when moving
  • Bloating
  • Constipation
  • Fever
  • Nausea and vomiting
  • Lack of energy
  • Lightheadedness
  • Shortness of breath
  • Fast heartbeat
  • Passing less urine


The doctor will ask about your symptoms and health history. A physical exam will be done.

Blood tests will be done.

Fluid may be taken from the peritoneum for testing. This can be done with paracentesis.

Images may be taken of the abdomen. This can be done with x-rays.

Surgery may be done to look inside the abdomen. This can be done with laparotomy.


The underlying cause will need to be treated. This may involve things like surgery to remove a ruptured appendix.

The goal of treatment is to ease inflammation. This can be done with antibiotics or antifungal medicine to treat infection.


There are no current guidelines to prevent this health problem.


American College of Gastroenterology
American Gastroenterological Association


Canadian Digestive Health Foundation


Marciano S, Díaz JM, et al. Spontaneous bacterial peritonitis in patients with cirrhosis: incidence, outcomes, and treatment strategies. Hepat Med. 2019;11:13-22.
Spontaneous bacterial peritonitis. EBSCO DynaMed website. Available at: Accessed March 23, 2021.
Spontaneous bacterial peritonitis (SBP). Merck Manual Professional Version website. Available at:
...(Click grey area to select URL)
Accessed March 23, 2021.
Last reviewed December 2020 by EBSCO Medical Review Board Daniel A. Ostrovsky, MD
Last Updated: 03/24/2021

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