Peritonitis Overview

Peritonitis is a serious disorder caused by an inflammation of the peritoneum, most often due to a bacterial infection. The peritoneum is a two-layered membrane that lines the abdominal cavity and encloses the stomach, intestines, and other abdominal organs. This membrane supports the abdominal organs and protects them from infection; however, occasionally the peritoneum itself may become infected by bacteria or other microorganisms.

Infection usually spreads from organs within the abdomen. The inflammation may affect the entire peritoneum or be confined to a walled-off, pus-filled cavity (abscess). A rupture anywhere along the gastrointestinal tract is the most common pathway for entry of an infectious agent into the peritoneum.

Peritonitis is a medical emergency: the muscles within the walls of the intestine become paralyzed and the forward movement of intestinal contents stops (ileus). However, since the advent of antibiotics, most people recover fully from peritonitis with proper treatment.

What Causes Peritonitis?

  • Many different types of bacteria can cause peritonitis, particularly those found within the intestine.
  • Tuberculosis and fungal and parasitical infections may cause a less acute form of peritonitis.
  • Perforation of the gastrointestinal tract, due to a stab or bullet wound, peptic ulcer, colon cancer, appendicitis, or diverticulitis, may allow bacteria-laden gastrointestinal contents to enter the abdominal cavity and cause peritonitis.
  • Abdominal surgery occasionally results in peritonitis.
  • Infection of the fallopian tubes, which are adjacent to the peritoneum, may cause peritonitis.
  • Cirrhosis of the liver may promote the development of bacterial peritonitis.
  • Systemic lupus erythematosus may cause a noninfectious inflammation of the peritoneum.

Symptoms of Peritonitis

  • Acute onset of severe, steady pain throughout the abdomen or localized pain in one area of the abdomen. Pain may persist for several hours and is worsened by movement or pressure on the abdomen.
  • Boardlike rigidity of the abdomen, due to contraction of the abdominal wall muscles
  • Swollen or bloated abdomen
  • Fluid in the abdomen
  • Inability to pass gas or stool
  • Chills and fever, with profuse perspiration
  • Nausea and vomiting
  • Weakness
  • Pale, cold skin
  • Shock

Peritonitis Prevention

  • Obtain prompt treatment for any infections or abdominal injuries or diseases.

Diagnosis of Peritonitis

  • Patient history and physical examination.
  • Abdominal x-rays, ultrasound exams, and CT (computed tomography) scans.
  • Blood tests will show an elevated white blood cell count.
  • Exploratory abdominal surgery (laparotomy) may be necessary.

How to Treat Peritonitis

  • Large doses of antibiotics are administered intravenously to treat bacterial peritonitis.
  • Surgery is often necessary when peritonitis is due to a disorder that has caused perforation along the intestinal tract; for example, a peptic ulcer or a burst appendix.
  • Intravenous fluids and feeding are usually necessary to prevent dehydration and give the intestines a rest.
  • Analgesics may be administered to reduce pain.
  • A tube passed through the nose into the intestine is attached to a suction device to remove contents from a temporarily paralyzed intestine.

When to Call a Doctor

  • EMERGENCY See a doctor or call an ambulance immediately if you experience severe abdominal pain that persists longer than 10 or 20 minutes, accompanied by any other symptoms of peritonitis.


Johns Hopkins Symptoms and Remedies: The Complete Home Medical Reference

Simeon Margolis, M.D., Ph.D., Medical Editor

Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50

Updated by Remedy Health Media

Publication Review By: the Editorial Staff at

Published: 24 Aug 2011

Last Modified: 22 Jul 2015