The authors deal with the incidence of sigmoid diverticulosis in Hungary. The pathomorphological types of the inflammatory complications (pericolic inflammation, abscess, abscess-phlegmon, chronic phlegmonic diverticulitis) are discussed in details. It is pointed out that besides the examinations available so far (irrigoscopy, colonoscopy), the clinical picture decided the question of whether or not the inflammatory complication required surgical treatment. CT examination offers a new possibility as well as an examination free of complication which furnishes more exact information as compared to every method used so far to the determination of the inflammation and thus to the decision of using surgical or conservative therapy.