Peritonitis is inflammation of the peritoneum, the thin membrane that lines the inside of the abdominal cavity.

What is going on in the body?

The peritoneum can become inflamed for various reasons. Infections of various types cause most cases of peritonitis. Peritonitis is quite painful, and often indicates the presence of a serious disease.

What are the causes and risks of the condition?

Most often, peritonitis is caused by an infection inside the abdomen. For example, appendicitis or other bowel infections can cause the problem. Other types of inflammation can also cause peritonitis without the presence of an infection. One of these is inflammation of pancreas, known as pancreatitis. Inflammation due to chemical irritants is another cause. Peritonitis can also be caused by irritation of the peritoneum from bleeding in the abdominal cavity, such as a ruptured ovarian cyst.