Stomal complications of ileostomy may occur many years after construction. An actuarial analysis of complications of 150 permanent end ileostomies constructed over a 10-year period is reported. By 20 years the incidence of stomal complications approached 76 per cent in patients operated on for ulcerative colitis and 59 per cent in those with Crohn's disease (P < 0.05). Revisional surgery rates were higher in patients with ulcerative colitis than in those with Crohn's disease (28 versus 16 per cent), albeit not significantly. The four commonest complications were skin problems (cumulative probability 34 per cent), intestinal obstruction (23 per cent), retraction (17 per cent) and parastomal herniation (16 per cent). Closure of the lateral space did not reduce the probability of developing intestinal obstruction (18 per cent at 20 years in those with closure versus 3 per cent in those without, P > 0.1). Fixation of the mesentery did not reduce the probability of developing prolapse of the ileostomy (11 per cent in those with fixation versus none in those without, P < 0.1). The incidence of parastomal herniation was not reduced by sitting through the rectus abdominis (21 per cent in those sited through the body of the rectus abdominis versus 7 per cent in those sited through the oblique muscles, P < 0.1). Some of the surgical dogmas relating to ileostomy construction are not supported by the results of this study.