COMPARISON BETWEEN THE COLONIC J-POUCH ANAL ANASTOMOSIS AND HEALTHY RECTUM - CLINICAL AND PHYSIOLOGICAL-FUNCTION

Background Colonic pouch anastomosis after restorative rectal excision obviates much of the early dysfunction which is commonly experienced with the traditional straight coloanal anastomosis. A disadvantage wit h colonic pouch reconstruction, however, appears to be impaired evacua tion. Methods Distal bowel function was investigated in 30 patients wi th a colonic J pouch anastomosis at 1 year after surgery and in 39 con trol subjects. Results While the degree of urgency and incontinence we re similar, the patients with a pouch experienced more difficult evacu ation. The maximum volume of the pouch (median 235 mi) and rectum (221 mi) was similar, but the rectum was more compliant (3.5 versus 2.6 mi per cmH(2)O, P < 0.01). The sensory function in terms of initial sens ation of filling, urge to defaecate and maximum distension pressure wa s impaired in those with pouches. The amplitude of the neorectal and a nal canal motility pattern was threefold that of controls. Maximum vol ume of the pouch was significantly associated with degree of impaired evacuation; the larger the volume the more difficult the evacuation. C onclusion To reduce evacuation difficulty the pouch should not be fash ioned too large. No conclusion about optimal pouch size could be drawn . In spite of fundamental physiological differences between a pouch an d healthy anorectum, patients with a colonic pouch will usually experi ence satisfactory clinical bowel function.