Animation of diverticula (pouches) in the wall of the large intestine. It is not known for sure why the intestinal wall forms these pouches, but they are quite common. Often the condition, known as diverticulosis, does not cause symptoms, although they may lead to bleeding from the rectum and abdominal cramps. The diverticula may also become infected, a condition known as diverticulitis, which causes pain, nausea, vomiting and constipation. Severe cases may lead to the perforation of the intestine wall, and resulting inflammation of the body cavity, which requires emergency treatment.