The "Hartmann operation" for complication of acute diverticulitis or obstruction of the rectosigmoid is a safe procedure with few complications. However, it needs a second operation to reconstruct the continuity of the intestinal tract with more difficulties. The goal of our report is to show the 30-day morbidity and the late sequelae after colostomy closure with special concern to the late anorectal function. We analyzed 43 patients who underwent colostomy closure after Hartmann's procedure between 1985 and 1990. We controlled personally 35 patients after 32 months (range: 5-64 months) concerning their bowel habits, anal sphincter function (digital measure) and endoscopic anastomosis diameter. There were no deaths, but there was a 9% perioperative morbidity (1 anastomotic leak, 1 anastomotic bleeding and 2 wound infections). In the further course 2/35 patients were incontinent for gas and liquid stool. Further 3 patients lost water after coughing and had a poor sphincter rest tone. Our results demonstrates a low 30-day morbidity after reversal of Hartmann's procedure. It needs further investigation to show, if a damaged sphincter muscle or a lower rectum capacity could be responsible for these results.