Peritonitis is the inflammation of the peritoneum, a membrane within the abdominal cavity. Causes are divided into infective (such as bacteria and parasites), and non-infective (such as leakage of gastrointestinal contents and toxic causes). If left untreated, peritonitis can rapidly become a serious threat to life, commonly from sepsis, as well as buildup of fluid or formation of abscesses.
Peritonitis is commonly treated initially with supportive care (fluid resuscitation, oxygen, analgesia), antibiotics (including those, such as metronidazole, which cover anaerobic bacteria common to the gut), and in severe cases surgery (laparotomy to identify and treat the source of the peritonitis).
The complications of peritonitis carry a significant mortality rate, due to septic shock and organ failure. In the US and western Europe, death from peritonitis occurs in around 10% of all cases, rising to over 40% in the elderly. Mortality and morbidity rates are significantly higher in non-industrialized countries where access to adequate medical facilities and medicines prevent adequate treatment.