The effect of a reversed ileal segment and artificial valve on intestinal transit and absorption following colectomy and low ileorectal anastomosis in the dog.

The main problem facing patients with ulcerative colitis after mucosal proctectomy and ileo-anal anastomosis (MP + IAA) is severe frequency of bowel action. Although the addition of a pelvic reservoir can improve matters, some patients still complain of this problem. In an attempt to slow transit, enhance absorption and improve function, we investigated the effects on these parameters of a reversed ileal segment, an artificial valve in an animal model. Studies were conducted before and after operation. The dogs randomly underwent either colectomy and low ileorectal anastomosis (IRA) alone (control, n = 12), IRA with a 10 cm reversed loop (IRA + RL, n = 10) or IRA with an artificial valve (IRA + valve, n = 10). Operative mortality rates were similar in the groups. Mean transit time (MTT) was significantly reduced after the control operation and after IRA + RL but not after IRA + valve. In addition MTT after IRA + valve (21 +/- s.d., 3.4 h) was significantly greater than in the other two groups (control = 12.1 +/- 4.3 h, IRA + RL, 12.8 +/- 5.5 h, P less than 0.04) and frequency of bowel actions seemed less. Measurements of absorption and nutritional state, however, did not differ significantly between the groups. Thus, although the artificial valve made no difference to absorption, it did prevent the reduction in MTT that occurred after the control operation whereas the reversed loop did not. This effect might thus benefit patients who undergo MP + IAA.