Peritonitis is the inflammation of the membrane that lines the abdominal cavity. It is usually caused by the release of digestive tract bacteria from the stomach or intestines due to an injury or perforation of these organs. However, it can have non-infectious causes such as the leakage of blood into the abdominal cavity, which soon become infected in this environment. In a healthy patient, the digestive tract properly segregates bacteria that are dangerous to the rest of the body from the bloodstream. However, when this barrier is broken, these bacteria multiply quickly in the abdominal cavity, and can often lead to additional complications, such as sepsis.
Several things can cause peritonitis. It is a common complication of a perforated gastric ulcer. It is also a common complication of abdominal surgery. It is almost certain to occur when a person suffers severe abdominal trauma, particularly a gunshot wound. In fact, most people who are shot die from peritonitis rather than from the trauma caused by the wound.
Peritonitis is very difficult to treat. Although broad spectrum antibiotics such as penicillin are usually effective against the bacteria, unless the underlying cause is treated, the bloodstream will continue to become infected. As such, surgery is usually required to search any perforations in the digestive tract or abdominal organs which must then be repaired.