What is peritonitis?

Peritonitis is a serious condition where the lining inside your abdomen and pelvis gets inflamed. This thin, silky tissue is called the peritoneum and covers:

• your stomach
• your liver
• other organs in your abdomen (belly)
• the inner wall of your abdomen

Peritonitis is life-threatening and needs immediate medical treatment.

What are the symptoms of peritonitis?

The most common symptom of peritonitis is severe abdominal pain that gets worse with movement. This makes you want to lie still.

Other common symptoms may include:

• a bloated belly
• fever
• nausea and vomiting
• loss of appetite
• diarrhoea
• feeling tired
• thirst and low urine (wee) output

Sometimes, you may have few or no symptoms.

What are the warning signs?

Warning signs of peritonitis that need immediate medical attention include:

• sudden and severe belly pain
• high fever
• hard or swollen belly
• difficulty passing wind or having a bowel movement

CHECK YOUR SYMPTOMS — Use the Symptom Checker and find out if you need to seek medical help.

When should I call an ambulance or go to the emergency department?

If you or someone you know has any symptoms of peritonitis, it is important to seek urgent medical care. Peritonitis can be life-threatening and requires fast treatment​.

Quick medical treatment may prevent serious problems such as infection spreading throughout the body.

This is especially important if you have severe liver cirrhosis or are on peritoneal dialysis, as you are at higher risk of peritonitis.

What should I do while waiting for the ambulance?

While waiting for the ambulance you can collect any relevant medical information, such as:

• a list of the person's medicines
• information on the person's allergies
• medical history

Do not give the person any food or drink. This could complicate their condition and interfere with potential treatments once they arrive at the hospital.

What causes peritonitis?

Inflammation of the lining of your abdomen is usually caused by a bacterial infection.

Bacteria can enter the abdomen from:

• a burst appendix or hole in the colon (burst intestinal diverticulitis)
• a perforated stomach (peptic) ulcer
• a ruptured ectopic pregnancy
• surgeries or injuries to the belly
• peritoneal dialysis
• pelvic inflammatory disease — where bacteria, often from a sexually transmitted infection (STI), enter through your vagina and reach the peritoneum in your pelvis

If you have liver cirrhosis, you may have a build-up of fluid in your abdomen, called ascites. This fluid may become infected without a clear source of where the bacteria have come from. This is called 'spontaneous bacterial peritonitis'. It can also happen in children with nephrotic syndrome (a type of kidney disease).

How is peritonitis diagnosed?

Your doctor will ask about your symptoms and medical history. They will also do a physical examination. Your doctor may refer you for tests if peritonitis is suspected, including:

• blood tests — to check for inflammation or bacteria in your bloodstream
• imaging tests — an ultrasound and CT scan may be used to check any holes or tears in the digestive tract
• peritoneal fluid analysis — a sample of fluid will be removed from your abdomen and tested

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How is peritonitis treated?

If you are diagnosed with peritonitis, you will need to stay in hospital for treatment, often in an intensive care unit.

Treatment may include:

• antibiotics given through an IV (a needle in your vein) to fight the infection quickly
• surgery — if peritonitis is caused by a hole in an organ, such as a burst appendix. This is needed to fix the hole and clean out the infection.
• drainage of any pockets of pus (abscesses) in your abdomen. Your doctor will use a needle, guided by an ultrasound or CT scan.

What are the complications of peritonitis?

Peritonitis can lead to serious complications if not treated quickly, such as:

• fluid buildup — fluid can collect in the abdomen, leading to dehydration
• sepsis — the infection can spread throughout the body, causing severe and widespread inflammation
• organ damage — sepsis can slow blood flow and reduce oxygen to tissues, causing organ failure and potentially death

Can peritonitis be prevented?

Prevention involves reducing your risk of infections. It also involves managing underlying conditions that could lead to peritonitis. Talk to your doctor to find out how to protect yourself.

Resources and support

• Sepsis Australia provides information and support to people who have sepsis and their carers.
• Visit the Liver Foundation to find out about preventing infection if you are living with chronic liver disease.
• You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available 24 hours a day, 7 days a week.

Looking for information for Aboriginal and/or Torres Strait Islander people?

NACCHO helps you find an Aboriginal Community Controlled Health Organisation (ACCHO) or Affiliate near you.