Diverticular disease is characterized by the formation of diverticula, or small out-pouchings and pockets, in the walls of the colon (the last segment of the gastrointestinal tract which digests and carries food through the body). There are three types of diverticular diseases: diverticulosis, diverticular bleeding, and diverticulitis. The specific causes of diverticular diseases are unknown, but they are more common in people with a low fiber diet, which leads to increased pressure in the colon resulting in pocket formation. In diverticulosis (uncomplicated diverticular disease) the pockets form but do not become infected or inflamed, and therefore no symptoms occur. Infection or inflammation of the pockets (diverticulitis) can cause abdominal (belly) pain, fever, as well as other complications that may require surgery. Diverticular bleeding results in blood in the stool and bleeding from the rectum and anus, and may also require immediate medical attention. Diverticular diseases are managed by maintaining a high fiber diet (e.g. grains, vegetables), although episodes of diverticulitis and diverticular bleeding may require antibiotics, hospitalization, and potentially surgery.