Alterations in the colon wall, motility disorders, and certain nutritional habits are the essential factors in the development of colon diverticula. Thus, with advancing age this results in a high incidence in Western industrialized countries. The clinical picture is usually one of symptom-free diverticulosis. Diverticular disease can be associated with minor symptoms, but in complicated cases with diverticulitis and diverticular hemorrhage, it is potentially fatal. Further complications include abscess formation, fistula development, and obstruction. Barium double-contrast imaging exhibits the highest diagnostic sensitivity in diverticulosis but is contraindicated in cases of suspected complicated diverticular disease due to the danger of perforation. In these instances, sonography, computed tomography, or magnetic resonance imaging are performed. For diverticular hemorrhage, coloscopy not only represents a possible diagnostic tool but also a therapeutic option for various techniques of hemostasis. Treatment of diverticulitis and its complications requires careful consideration of conservative and surgical approaches and close indisciplinary cooperation.