Peritonitis: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Peritonitis?
A general surgeon (a doctor who operates on the belly) usually treats peritonitis. It needs emergency treatment in most cases. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is peritonitis?
Peritonitis is an inflammation (irritation) of the peritoneum. The peritoneum is the thin tissue that lines the inner wall of the abdomen and covers most of the abdominal organs. Peritonitis is present when this tissue becomes inflamed or infected. Peritonitis can be life threatening and may cause complications.
One type is called spontaneous bacterial peritonitis (SBP). Secondary peritonitis is peritonitis that comes from another problem.
Symptoms
Symptoms of peritonitis can include:
- A belly that is very painful or tender, with pain that may get worse when the belly is touched or when you move.
- A belly that looks or feels bloated.
- Fever and chills.
- Passing little or no stools or gas.
- Passing less urine.
- Nausea and vomiting.
- A racing heartbeat.
- Shortness of breath.
- Decreased appetite.
- Excessive tiredness.
Causes and who gets it
Peritonitis is caused by a collection of blood, body fluids, or pus in the belly. SBP happens in people with ascites. Ascites is a buildup of fluid between the lining of the belly and the organs. Ascites is found in people with long-term liver damage, certain cancers, and heart failure.
Secondary peritonitis can follow other problems, such as:
- Trauma or wounds to the belly.
- A hole in the intestine.
- A ruptured appendix.
- A stomach ulcer or a hole in the colon that lets bacteria into the peritoneum.
- Infection after belly surgery.
- Pancreatitis, which is swelling of the pancreas. It can let chemicals leak into the belly.
- Tubes placed into the belly, such as feeding tubes.
How doctors diagnose it
A provider will do a physical exam. The belly is usually tender and may feel firm or board-like. People with peritonitis usually curl up or refuse to let anyone touch the area.
A provider may also find fever, a fast heart rate, fast breathing, low blood pressure, and a tender, swollen belly. Blood tests, x-rays, and CT scans may be done. If there is a lot of fluid in the belly area, a provider may use a needle to remove some and send it for testing.
Treatment
The cause must be found and treated right away. Treatment typically involves surgery, antibiotics, or both. Surgery is often needed to treat the source of infection, like an infected bowel.
General treatment also includes fluids through a vein (IV), pain medicines, and sometimes a tube through the nose into the stomach. The outcome can range from complete recovery to overwhelming infection and death. The outcome depends on how long symptoms lasted before treatment and on the person's general health.
Complications may include dead bowel tissue that needs surgery. They may also include adhesions, which can cause a bowel blockage in the future.
When to see a doctor
Call 911 or go to the emergency room if you have symptoms of peritonitis. It is serious and needs emergency treatment in most cases.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Peritonitis needs emergency care in most cases, so the first step is the emergency room. Afterward, such a doctor can help with follow-up and with long-term health problems.
Common questions
Is peritonitis life threatening?
Yes, peritonitis can be life threatening. The outcome can range from complete recovery to overwhelming infection and death. How long symptoms were present before treatment began is one thing that affects the outcome.
Does peritonitis always need surgery?
No, treatment typically involves surgery, antibiotics, or both. Surgery is often needed to remove or treat the source of infection.
What is spontaneous bacterial peritonitis?
SBP is a type of peritonitis that occurs in people with ascites. Ascites is a buildup of fluid in the space between the lining of the belly and the organs. It is found in people with long-term liver damage, certain cancers, and heart failure.
Can a ruptured appendix cause peritonitis?
Yes, a ruptured appendix can cause a hole in the digestive tract that lets bacteria enter the peritoneum. This is called secondary peritonitis.
Sources
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
