Written by Ann Pietrangelo | Published on July 18, 2012
Medically Reviewed by George Krucik, MD


You have a thin layer of tissue covering the inside of your abdomen and most of its organs. This is called the peritoneum. Inflammation of the peritoneum is called peritonitis. The inflammation is caused by a fungal or bacterial infection, usually due to an injury to your abdomen, an underlying medical condition, or a treatment device, such as a dialysis catheter or feeding tube.

Peritonitis is a serious condition that requires immediate medical care. Antibiotics are usually used to treat the infection, but surgery is sometimes required to remove infected tissue. If not treated promptly, the infection can spread and become life threatening.

What Causes Peritonitis?

There are two types of peritonitis. Spontaneous peritonitis is caused by an infection of the fluid in your peritoneal cavity. This can be caused by liver or kidney failure. People on peritoneal dialysis for kidney failure are also at risk.

Secondary peritonitis is usually caused by an infection that has spread from your digestive tract.

The following conditions can cause peritonitis:

  • an abdominal wound or injury
  • a ruptured appendix
  • a stomach ulcer
  • a perforated colon
  • diverticulitis (when pouches form on the wall of your colon and become inflamed)
  • pancreatitis (inflammation of the pancreas)
  • cirrhosis of the liver or other liver disease
  • infection of the gallbladder, intestines, or bloodstream
  • pelvic inflammatory disease (infection of a woman’s reproductive organs)
  • Crohn’s disease (a type of inflammatory bowel disease)
  • medical procedures, including treatment for kidney failure, surgery, or the use of a feeding tube

Symptoms of Peritonitis

Symptoms will vary depending on the underlying cause of your infection. Common symptoms of peritonitis include:

  • tenderness in the abdomen
  • pain in the abdomen that gets more intense with motion or touch
  • abdominal bloating or distention
  • nausea and vomiting
  • diarrhea
  • constipation or the inability to pass gas
  • passing only a small amount of urine
  • poor appetite
  • excessive thirst
  • fatigue
  • fever and chills

If you are on peritoneal dialysis, your dialysis fluid may appear cloudy or have white flecks or clumps in it. You may also notice redness or feel pain around your catheter.

Diagnosing Peritonitis

If you have symptoms of peritonitis, seek medical attention right away. Delaying your treatment could put your life at risk.

Your doctor will take down your medical history and give you a complete physical exam. This will include touching or pressing on your abdomen, which will probably cause some discomfort.

Other tests used to help diagnose peritonitis are:

  • Blood tests: A blood test can measure your white blood cell count. A high count usually signals inflammation or infection. A blood culture can help to identify the bacteria causing the infection or inflammation.
  • Fluid analysis: If you have a build-up of fluid in your abdomen, your doctor can use a needle to remove some and send it to a laboratory. Culturing the fluid can also help identify bacteria.
  • CT scan, X-ray: Imaging tests can show any perforations or holes in your peritoneum.

If you are on dialysis, your doctor may diagnose you based on the cloudy dialysis fluid.

How Peritonitis Is Treated

The first step in treating peritonitis is determining its underlying cause. Treatment usually involves antibiotics to fight infection and medication for pain.

If you have infected bowels, an abscess (a collection of pus), or an inflamed appendix, you may need surgery to remove the infected tissue.

If you are on kidney dialysis and are diagnosed with peritonitis, you may have to wait until the infection clears up to receive more dialysis. If the infection continues, you might need to switch to a different type of dialysis.

Your treatment must begin promptly to avoid serious and potentially fatal complications.

Complications from Peritonitis

If not treated promptly, the infection may enter your bloodstream, causing shock and damage to other organs, which can be fatal.

The potential complications of spontaneous peritonitis include:

  • hepatic encephalopathy (loss of brain function when the liver can no longer remove toxic substances from your blood)
  • hepatorenal syndrome (progressive kidney failure)
  • sepsis (a severe reaction in which the bloodstream becomes overwhelmed by bacteria)

Complications of secondary peritonitis include:

  • an abscess (a collection of pus)
  • gangrenous bowel (dead bowel tissue)
  • intraperitoneal adhesions (bands of fibrous tissue that join abdominal organs and can cause bowel blockage)
  • septic shock (dangerously low blood pressure)

Prognosis for Peritonitis

Your prognosis will depend on the cause of your infection and how far it progressed before treatment began. Medications and surgery are usually able to bring the infection under control.

If treatment does not begin early, the infection can spread. If other organs are damaged, your prognosis will depend on how much damage was done and on your overall health.

How to Prevent Peritonitis

If you are on dialysis, take care to wash your hands (including your fingernails), before touching your catheter. Clean the skin around the catheter daily. Follow your doctor’s instructions regarding the care and storage of your medical supplies.

See your doctor, go to an emergency room, or call 911 if you have severe abdominal pain or have received an abdominal injury, such as a knife wound.

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