Peritonitis (per-i-to-NI-tis) is an inflammation * of the peritoneum (perito-NEE-um), which is the lining of the abdominal (ab-DAH-mih-nul) cavity. Peritonitis typically results from a hole or slit in one of the hollow organs of the abdomen, which include the stomach, small intestine, colon, and gallbladder. This hole can allow the contents of the organ, often including billions of bacteria, to escape into the abdominal cavity. Peritonitis can be life threatening.

What Is Peritonitis?

Peritonitis is an inflammation of the peritoneum, the thin, slippery abdominal lining that covers the organs in the abdomen. While peritonitis may not sound serious, it is very dangerous if it is not identified and treated right away. Anyone with symptoms of peritonitis needs emergency medical attention immediately.

Usually, the cause of peritonitis is a perforation (per-fo-RAY-shun), or a hole, in the stomach, intestines, appendix, or one of the other organs covered by the lining. The perforation can come from a disease process such as stomach or intestinal ulcer * , Crohn's disease * , or ulcerative colitis * ; ulcerative gallbladder * disease; a knife or gunshot wound to the abdomen; or from a cut during surgery. When such a perforation occurs, bacteria * can quickly invade the abdominal cavity. For example, a puncture in the colon (the part of the intestine that stores feces before it leaves the body) can send billions and even trillions of bacteria and bacterium-like cells flooding into the abdomen. The peritoneum mounts a defense against the onslaught, and peritonitis results.

People can also get peritonitis from complications of a wide variety of other illnesses, including the following.

In all of these cases, bacteria can inflame the peritoneum. People with cirrhosis * (sir-O-sis) of the liver * sometimes get spontaneous bacterial peritonitis, which means that they have no rupture or obvious source for the infection.

What Happens When People Get Peritonitis?


The symptoms of peritonitis range from mild to excruciating pain in the stomach area, and while the pain may start in one area, it often extends throughout the abdomen * within a matter of hours. Movement or touching the abdomen typically makes the pain worse. A person with peritonitis usually loses his or her appetite and may quickly become nauseated. Some may begin vomiting. Peritonitis often causes a muscle spasm in the abdominal wall, making the abdomen feel hard and immobile, as if it were a wooden board. The stomach may also become distended (puffed out).


A doctor often can diagnose peritonitis through a physical examination of the patient. Doing so may include gently touching the abdomen both to determine the level of pain and tenderness (typically very severe) and to check for hardness (called rigidity). To confirm the diagnosis, the doctor may also order blood tests, abdominal x-rays, or CT scans * .


The treatment of peritonitis usually includes surgery and antibiotics * . The surgeon repairs any ruptured organ that caused the inflammation, and also washes and drains the infectious fluids from the abdominal cavity. Antibiotics treat the bacterial infection. Most people who get peritonitis recover fully after treatment. Without prompt treatment, however, peritonitis can be fatal, so people who have symptoms of peritonitis should receive immediate medical attention.

See also Appendicitis • Bacterial Infections • Cirrhosis of the Liver • Diverticulitis/Diverticulosis • Gallbladder Disease • Infection • Pelvic Inflammatory Disease (PID) • Sepsis


Books and Articles

Bali, Rajandeep Singh, et. al. “Perforation Peritonitis and the Developing World.” International Scholarly Research Notices. April 2, 2014. (accessed March 18, 2016).

Farcy, David A., et al., editors. Critical Care Emergency Medicine. 2nd ed. New York: McGraw-Hill Education, 2016.


Better Health Channel. “Peritonitis.” Victoria State Government Department of Health. (accessed March 18, 2016).

NHS Choices. “Peritonitis.” National Health Services. (accessed March 18, 2016).

University of Maryland Medical Center. “Peritonitis.” (accessed March 18, 2016).


American College of Gastroenterology. 6400 Goldsboro Rd., Suite 200, Bethesda, MD 20817. Telephone: 301-263-9000. Website: (accessed March 18, 2016).

U.S. National Library of Medicine. 8600 Rockville Pike, Bethesda, MD 20894. Toll-free: 888-346-3656. Website: (accessed March 18, 2016).

* inflammation (in-fla-MAY-shun) is the body's reaction to irritation, infection, or injury that often involves swelling, pain, redness, and warmth.

* ulcer is an open sore on the skin or the lining of a hollow body organ, such as the stomach or intestine. It may or may not be painful.

* Crohn's disease (KRONZ) is an often inherited, chronic inflammatory disease that typically affects the small and/or large intestine but can affect any part of the digestive system. The disease causes crater-like ulcers or sores in the inner surface of the bowel. Mild cases may be treated with medication; serious cases may be treated with surgery.

* colitis, ulcerative (ko-LIE-tis, UL-sirah-tiv) is a common form of inflammatory bowel disease that causes inflammation with sore spots or breaks in the inner lining of the large intestine (colon). Symptoms include cramping, bleeding from the rectum, and diarrhea.

* gallbladder is a small pearshaped organ on the right side of the abdomen that stores bile, a liquid that helps the body digest fat. * bacteria (bak-TEER-ee-a) are single-celled microorganisms, which typically reproduce by cell division. Some, but not all, types of bacteria can cause disease in humans. Many types can live in the body without causing harm.

* cirrhosis (sir-O-sis) is a condition that affects the liver, involving long-term inflammation and scarring, which can lead to problems with liver function.

* liver is a large organ located beneath the ribs on the right side of the body. The liver performs numerous digestive and chemical functions essential for health.

* abdomen (AB-do-men), commonly called the belly, is the portion of the body between the thorax (THOR-aks) and the pelvis.

* CT scans, or computed tomography (to-MOG-ra-fee) scans, use computers to view structures inside the body. Formerly called computerized axial tomography (CAT).

* antibiotics (an-tie-by-AH-tiks) are drugs that kill or slow the growth of bacteria.

Disclaimer:   This information is not a tool for self-diagnosis or a substitute for professional care.

(MLA 8th Edition)