Occasionally they affect the small intestine, as well.
Diverticulosis is thought to be caused by a diet that is low in fiber.
The use of strong laxatives and straining of the abdominal muscles from the resulting constipation causes increased pressure in the colon. This excess pressure causes the weak spots in the colon to bulge out and become diverticula. When these pouches become inflamed, the condition is called diverticulitis. Diverticulitis can lead to complications such as infections, perforations or tears, blockages or bleeding. Diverticulosis affects more women than men and becomes more common with increasing age.