From February 1989 to February 1982, 23 pseudocontinent perineal colostomies (PC), performed after abdominoperineal excision for rectal carcinoma, were evaluated. Perineal colostomy was performed using a free autotransplant of smooth muscle, according to Schmidt, associated with colonic irrigations. This procedure was proposed to the younger and more alert patients without advanced rectal carcinoma. These 23 cases represented 35% of the rectal extirpations performed during the same period. Four patients did not accept a PC and preferred, after being fully informed about both types of colostomies, to have a classical iliac colostomy which they thought to be safer. The advantages of this procedure were mainly psychological, as the body scheme and corporeal image were not disturbed. Continence was evaluated in only 21 cases, because two patients had non-specific complications (necrosis of the colonic extremity, and colonic perforation due to enema material). Ten patients were incontinent to flatus, but did not have to wear a sanitary towel, while 11 patients had occasional, minor soiling, requiring the use of a sanitary towel. None of the patients had major incontinence requiring a secondary iliac colostomy. When asked what they thought of results, none said that they were dissatisfied. The degree of satisfaction was subjective and was not correlated with the quality of functional results as seven patients declared themselves satisfied although they had minor soiling, and conversely, two patients were not completely satisfied, even though they had no soiling. Six months after operation, the muscular transplanted ring had disappeared in half of the patients, but this did not seem to have any repercussion of the quality of functional results.(ABSTRACT TRUNCATED AT 250 WORDS)