Ulcerative colitis and polyposis are both diseases of the mucosa. They can be cured by colectomy combined with selective mucosal proctectomy, without sacrifice of teh anal sphincters or damage to bladder or sexual function. Terminal ileum, either as a straight tube or in the form of a pouch, is drawn down through the denuded tube of anorectal muscle and anastomosed to the mid-anal canal. A temporary defunctioning ileostomy is always used. Caecum has also been used as a neorectum after mucosal proctectomy, but without long term success. Twenty-two patients, 20 with ulcerative colitis and 2 with polyposis, have been treated by mucosal proctectomy in the past 4 years, with no mortality. The caeco-anal procedure proved a failure because of recurrence of colitis, although the early functional results were good. After ileo-anal anastomosis, continence was perfect by day, but 2 patients had occasional lapses at night. The disadvantage of straight ileo-anal anastomosis is frequency of bowel action (6-9 times a day), even with codeine medication, although the patients considered the operation a success. Some form of pelvic reservoir is therefore desirable and our early experience with the triplicated ileal pouch is encouraging.