Surgical treatment of acute SD is more effective in preventing an eventual relapse of SD than conservative treatment, particularly in patients with recurrent and severe diverticulitis. The necessity for an emergency operation during follow-up is low and did not differ between the two treatment groups. The initial clinical presentation of SD is not a strong predictor of recurrence.

A total of 257 patients (142 male and 115 female; mean age, 56.6 years) underwent surgery (116 early elective and 141 late elective) for phlegmonous and covered perforated SD. Phlegmonous SD was seen in 127 cases and covered perforated SD in 130 cases. In the phlegmonous type of SD, early surgery led to conformity with the preoperative stage in 56%, to more extensive findings in 11%, and to subsided inflammation in 33%. Late surgery led to conformity in 0% and to signs of subsided inflammation in 100%. In the covered perforated type of SD, early surgery led to conformity in 90%, to subsided inflammation in 10%, and to milder manifestation in 0%. In contrast, late surgery here led to conformity in 26% of the cases and to subsided inflammation in 74%. Considerable histological changes can be detected under conservative therapy. The acute inflammation subsides under antibiotic therapy as awaited. It must be clarified whether the phlegmonous form of SD should, in principal, be regarded as an indication for surgery, since it shows early and nearly complete regression of the inflammation. Otherwise, the covered perforated type of SD still shows marked inflammatory changes after conservative therapy in a high percentage of patients and should thus preferably be treated by surgery. However, the clinical appearance of the patient with sigmoid diverticulitis still remains the most important part of decision making.

Surgical treatment of acute SD is more effective than conservative therapy for the prophylaxis of recurrent SD and avoidance of persistent symptoms.