The peritoneum is the thin tissue that lines the inner wall of the abdomen and covers most of the organs in the abdomen. Peritonitis is present when this tissue becomes inflamed or infected.
Spontaneous bacterial peritonitis (SBP) is present when this tissue becomes infected and there is no clear cause.
Causes
SBP is most often caused by infection in fluid that collects in the peritoneal cavity (ascites). The fluid buildup often occurs in people with advanced liver or kidney disease.
Risk factors for liver disease include:
- Very heavy alcohol use
- Chronic hepatitis B or hepatitis C
- Other diseases that lead to cirrhosis
SBP also occurs in people who are on peritoneal dialysis for kidney failure.
Peritonitis may have other causes in which case it is called secondary peritonitis. These include infection from other organs or leakage of enzymes or other toxins into the abdomen.
Symptoms
Symptoms include:
- Abdominal pain and bloating
- Abdominal tenderness
- Fever
- Low urine output
Other symptoms include:
Exams and Tests
Tests will be done to check for infection and other causes of abdominal pain:
- Blood culture
- White blood cell count in a sample of peritoneal fluid (a neutrophil count greater than 250 cells per cubic millimeter is diagnostic for SBP)
- Chemical examination of peritoneal fluid
- Culture of peritoneal fluid
- CT scan or ultrasound of the abdomen
Treatment
Treatment depends on the cause of the SBP.
- Surgery may be needed if SBP is caused by a foreign object, such as a catheter used in peritoneal dialysis.
- Antibiotics to control infection.
- Intravenous albumin to help reduce the risk for kidney failure and death.
You will need to stay in the hospital so health care providers can rule out other causes such as a ruptured appendix and diverticulitis.
Outlook (Prognosis)
In most cases, the infection can be treated. However, kidney or liver disease may limit recovery.
Possible Complications
Complications may include:
- Loss of brain function occurs when the liver is unable to remove toxins from the blood.
- Kidney problem caused by liver failure.
- Sepsis.
When to Contact a Medical Professional
Contact your provider if you have symptoms of peritonitis. This can be a medical emergency situation.
Prevention
Steps should be taken to prevent infection in people with peritoneal catheters.
Long-term antibiotics may be used:
- To prevent peritonitis from coming back in people with liver failure
- To prevent peritonitis in people who have acute gastrointestinal bleeding due to other conditions
Alternative Names
Spontaneous bacterial peritonitis (SBP); Ascites - peritonitis; Cirrhosis - peritonitis
Images
References
Garcia-Tsao G. Cirrhosis and its sequelae. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 139.
Kuemmerle JF. Inflammatory and anatomic diseases of the intestine, peritoneum, mesentery, and omentum. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 128.
Pose E, Juanola A, Gines P. Ascites and spontaneous bacterial peritonitis. In: Chung RT, Rubin DT, Wilcox CM, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease. 12th ed. Philadelphia, PA: Elsevier; 2026:chap 95.
Review Date 4/27/2026
Updated by: Todd Eisner, MD, Private practice specializing in Gastroenterology in Boca Raton and Delray Beach, Florida at Gastroenterology Consultants of Boca Raton. Affiliate Assistant Professor, Florida Atlantic University School of Medicine. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.