Secondary peritonitis is an inflammation (irritation) of the peritoneum (the membrane lining the abdominal cavity) caused by another condition, most commonly the spread of an infection from the digestive organs or bowels.

Secondary peritonitis has several major causes. Bacteria may enter the peritoneum via a hole (perforation) in the gastrointestinal tract, which can be caused by a ruptured appendix, stomach ulcer or perforated colon. The condition can also occur when pancreatic enzymes leak into the peritoneum during pancreatitis or when bile leaks from the biliary tract due to injury, because these chemicals can irritate the peritoneum.

Foreign contaminants can also cause secondary peritonitis if they get into the peritoneal cavity. This can occur during use of peritoneal dialysis catheters.

Inflammation of the peritoneal cavity caused by bacteria can result in infection of the bloodstream (sepsis) and severe illness.

Secondary peritonitis can also affect premature babies who have necrotizing enterocolitis.

• Abdominal pain
• Abdominal distention
• Fever
• Thirst
• Low urine output

Vital signs (temperature, pulse, rate of breathing, blood pressure) may show fever, rapid heart rate and breathing, and low blood pressure.

Tests your doctor may order:

• Blood tests for white cell count (a marker of infection)
• X-rays or CAT scan
• Blood culture
• Peritoneal fluid culture