Assessment of anorectal function in selection of patients for ileorectal anastomosis in Crohn's colitis.

Anorectal function has been assessed in 53 patients with Crohn's disease by measurement of resting and squeeze anal canal pressures and the maximum volume tolerated during distension of a balloon in the rectum. Radiographs of the rectum from barium enema examination were also reviewed to assess rectal capacity. Thirty-three patients have had a colectomy and ileorectal anastomosis for Crohn's colitis of whom 13 now have a stoma because they either required a protectomy (n=9) or where closure of a loop ileostomy had not been possible (n=4) because of severe anorectal disease. The maximum tolerated volume was less than 150 ml in 12 of 13 patients who now have a stoma compared with none of the 20 patients who have a functioning anastomosis. Although the correlation between a radiological assessment of rectal capacity and the maximum tolerated volume was poor, a severely contracted rectum was associated with the need for a stoma in six of seven patients compared with only two of 13 patients who did not have radiological signs of a narrow rectum.