One hundred and fifteen patients who were treated by a proctocolectomy in Oxford between 1972 and 1984 for inflammatory bowel disease have been studied. All the patients had the rectum removed by the technique of perimuscular dissection which was introduced in 1972 in an attempt to overcome the problems associated with the previous types of proctectomy. The method has been shown to be safe; the operative mortality was 1.7 per cent. The most worrying potential complications due to permanent autonomic nerve damage (i.e. impotence and urinary incontinence), which previously have been recorded as occurring in a significant percentage of patients, were completely prevented by the method of dissection. One man suffered transient impotence which responded to psychiatric treatment. There were no long term urinary tract or sexual problems. Postoperative complications occurred in 37 per cent of patients, perineal wound infections being the most common (25.7 per cent). Perineal healing, however, was achieved in 75 per cent of patients by the time of their discharge from hospital. The mean length of postoperative hospital stay was 19 days in patients with ulcerative colitis and 15 days in patients with Crohn's disease. Our rate of perineal healing is better than has been recorded using other operative techniques.