Diverticulosis is found in approximately 5% of people living in western industrialized countries. 95% of these are without any symptoms and do not need any therapy. For prophylaxis of diverticulitis a diet containing non-digestable cellulose and swelling substances is recommended. Complications of diverticulosis like diverticulitis, perforation abscess, or stenosis can necessitate a resection of the sigmoid colon. This should be done before life-threatening complications like free perforation or massive bleeding occur.