Acute abdomen

Alternative names

Peritonitis is an inflammation (irritation) of the peritoneum, the membrane that lines the wall of the abdomen and covers the abdominal organs.

Causes, incidence, and risk factors
Types of peritonitis include:

  • Peritonitis - spontaneous  
  • Peritonitis - secondary  
  • Peritonitis - dialysis associated

Intra-abdominal abscess (abdominal abscess) involves a collection of pus in the abdomen, which may cause peritonitis. Before peritonitis develops, the abscess may still cause symptoms similar or identical to peritonitis.


  • Abdominal pain or tenderness  
  • Abdominal distention  
  • Fever  
  • Low urine output  
  • Nausea and vomiting  
  • Point tenderness  
  • Thirst  
  • Fluid in the abdomen  
  • Inability to pass feces or gas

Additional symptoms that may be associated with this disease include:

  • Cloudy dialysis fluid (if undergoing peritoneal dialysis)  
  • Nausea and vomiting  
  • Shaking chills  
  • Signs of shock

Signs and tests

Examination of the abdomen typically shows tenderness. The abdomen may feel firm and “board-like” and there may be extensive “guarding” (protective movements such as curling up or refusal to allow the abdomen to be touched).

Blood tests and x-rays or CT scans may be ordered.


The cause must be identified and treated promptly.

Treatment typically involves surgery and antibiotics. In cases associated with peritoneal dialysis, antibiotics may be infused through the dialysis catheter, but if the infection is severe, the catheter itself must often be removed.

Expectations (prognosis)
The outcome is often good with treatment, poor without treatment. Sometimes, however, the outcome is poor even with prompt and adequate treatment.

Peritonitis can be life-threatening and cause a number of different complications, depending on the type.

Calling your health care provider

Go to the emergency room or call the local emergency number (such as 911) if you have symptoms that may indicate peritonitis, as it is a medical emergency.

Prevention depends on the cause. See the specific types of peritonitis.

Johns Hopkins patient information

Last revised:

Diseases and Conditions Center

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.