SummaryThe author describes retrorectal lowering of the colon with a temporary perineal colostomy, a modification of the Duhamel operation. The modification increases patient comfort by eliminating the original crushing clamps and renders the rectocolic anastomosis more secure.The perineal colostomy is resected between the seventh and the fifteenth postoperative days with an inverted “V” segment of the rectocolic septum, and the entire contour of the anastomosis is sutured with chromic catgut. The surgeon can delay as long as he feels necessary the resection of the perineal colostomy.The author describes the results of this procedure used in 50 patients with acquired megacolon. There was no leakage at the rectocolic anastomosis. Partial leakage of the rectal‐stump suture line was observed in five patients, in all of whom the section and suture of the rectum had been made at the level or below the peritoneal reflection. Fecal impaction in the rectal stump occurred in five cases; in these patients the section and suture of rectum had been high enough to maintain a blind space between the suture and the first Houston valve; fecal impaction occurred in the blind space.To prevent leakage of the rectal‐stump suture, the section and suture must be 3 to 6 cm above the peritoneal reflection. To prevent fecal impaction the blind space which remains between the first Houston valve and the suture of the rectal stump should be suppressed by a more invaginating second‐layer suture of the stump.