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Peritonitis is an inflammation (irritation) of the peritoneum. This is the thin tissue that lines the inner wall of the abdomen and covers most of the abdominal organs.


Peritonitis is caused by a collection of blood, body fluids, or pus in the abdomen (intra-abdominal abscess).

Types of peritonitis are:


The belly (abdomen) is very painful or tender. The pain may become worse when the belly is touched or when you move.

Your belly may look or feel bloated. This is called abdominal distention.

Other symptoms may include:

Exams and Tests

The doctor or nurse will perform a physical exam. The abdomen is usually tender. It may feel firm or "board-like." Persons with peritonitis usually curl up or refuse to let anyone touch the area.

Blood tests, x-rays, and CT scans may be done. If there is a lot of fluid in the belly area, the doctor may use a needle to remove some and send it for testing.


The cause must be identified and treated promptly. Treatment typically involves surgery and antibiotics.

Possible Complications

Peritonitis can be life-threatening and may cause complications. These depend on the type of peritonitis.

When to Contact a Medical Professional

Go to the emergency room or call the local emergency number (such as 911) if you have symptoms of peritonitis.

Alternative Names

Acute abdomen


Badgwell B, Turnage RH. Abdominal Wall, umbilicus, peritoneum, mesenteries, omentum, and retroperitoneum. In: Townsend CM Jr, Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery

Prather C. Inflammatory and anatomic diseases of the intestine, peritoneum, mesentery, and omentum. In: Goldman L, Schafer AI, eds.Goldman's Cecil Medicine

Update Date 4/9/2014

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