Last reviewed 01/2018

Peritonitis is defined as inflammation of the peritoneal cavity. The peritoneal cavity includes an extensive serous membrane that covers the entire abdominal wall and is reflected over the contained viscera, the greater and lesser omentum, and the transverse mesocolon.

In early peritoneal inflammation, the condition is often localised because of containment of the affected area by surrounding structures e.g. omentum, adjacent bowel and fibrinous adhesions. However, this may not be sufficient to contain the inflammation and a condition that initially presented with localised peritonitis may eventually develop into generalised peritonitis. Precipitating factors include abrupt contamination, as occurs with penetrating wounds, continuing contamination from a large bowel defect, the bursting of a localised abscess, or the secondary infection of ascitic fluid.