THE EFFECT OF HYSTERECTOMY ON ANORECTAL PHYSIOLOGY

Hysterectomy is associated with severe constipation in a subgroup of p atients, and an adverse effect on colonic motility has been described in the literature. The onset of irritable bowel syndrome and urinary b ladder dysfunction has also been reported after hysterectomy. In this prospective study, we investigated the effect of simple hysterectomy o n ano-rectal physiology and bowel function. Thirty consecutive patient s were assessed before and 16 weeks after operation. An abdominal hyst erectomy was performed in 16 patients, and a vaginal procedure was per formed in 14. The parameters measured included the mean resting, and m aximal forced voluntary contraction anal pressures, the recto-anal inh ibitory reflex, and rectal sensation to distension. In 8 patients, the terminal motor latency of the pudendal nerve was assessed bilaterally . Pre-operatively, 8 patients were constipated. This improved followin g hysterectomy in 4, worsened in 2, and was unchanged in 2. Symptomato logy did not correlate with changes in manometry. Although, the mean r esting pressure was reduced after hysterectomy (57 mmHg- 53 mmHg, P=0. 0541), the maximal forced voluntary contraction pressure was significa ntly decreased (115 mmHg- 105 mmHg, P=0.029). This effect was more pro nounced in those with five or more previous vaginal deliveries (P=0.02 44, n=9). There was no significant change in the number of patients wi th an intact ano-rectal inhibitory reflex after hysterectomy. There wa s no change in rectal sensation to distension, and the right and left pudendal nerve terminal motor latencies were unaltered at follow-up. O ur results demonstrate that hysterectomy causes a decrease in the maxi mal forced voluntary contraction and pressure, and this appears to be due to a large decrease in a small group of patients with previous mul tiple vaginal deliveries.