Background: This study was designed to evaluate the natural history of patients admitted for acute diverticulitis.
Methods: Nine hundred and seventy-seven patients admitted to Oulu University Hospital for acute symptoms of diverticular disease during the 20-year period from 1986 to 2005 were identified using a database.
Results: Six hundred and ninety-five patients were admitted for uncomplicated diverticulitis and 282 for complicated diverticulitis. The patients admitted for uncomplicated diverticulitis were younger than the others and 66% of them were admitted only once. The number of admissions preceding perforation was higher in the 1980s, and the number of admissions was unrelated to the degree of perforation or the outcome of the patients. The annual prevalence of sigmoid diverticular perforation increased from 2.6/100,000 in 1986 to 4.2/100,000 in 2005. Seventy (10%) of the 695 patients admitted for the first time for acute diverticulitis underwent urgent surgery during the same admission and 66 (9%) had elective surgery during a later admission. Overall hospital mortality was 2.3%, being 1% among those admitted for acute diverticulitis and 5.5% among those admitted for diverticular perforation. Two hundred and thirty-four (42%) of the 555 nonoperated patients with acute diverticulitis developed a recurrent episode of diverticulitis. The course of recurrent disease was similar to the primary episode.
Conclusion: Two or more preceding admissions for acute diverticulitis do not warrant sigmoid resection after diverticulitis. Young patients do not have a greater risk of complicated diverticulitis than older ones.