Comparison of colonic reservoir and straight colo-anal reconstruction after rectal excision.

The clinical and physiological results in 13 patients having a colonic J reservoir-anal anastomosis (CR) and 15 consecutive patients having a straight colo-anal reconstruction (SC) have been compared. The groups were matched for age, sex, level of tumour and proximal and distal resection margins. The incidence of postoperative complications was similar in each group. The mean follow-up in CR patients was 7 +/- 4 months and 47 +/- 23 months in SC patients. Stool frequency per 24 h was less than or equal to 2 in all CR patients while it was greater than 2 in 40 per cent of the SC patients (P less than 0.05). Three CR patients and six SC patients had minor incontinence, all but one of the rest were fully continent. One patient had a major leak. There was no significant difference in mean resting anal voluntary contraction pressure in the two groups, with mean values within the normal range. The mean rectal sensitivity threshold volume in CR patients (83 +/- 30 ml) and SC patients (52 +/- 22 ml) was significantly different (P less than 0.05) as was the mean maximum tolerable volume (317 +/- 122 ml and 174 +/- 83 ml respectively, P less than 0.01). There was no significant difference in balloon expulsion testing, defaecating proctography or methyl cellulose evacuation in the two groups. The addition of a colonic reservoir appears to avoid the high stool frequency occurring in some patients after straight colo-anal anastomosis.