Preservation of complete anal sphincteric proprioception in restorative proctocolectomy: the inhibitory reflex and fine control of continence need not be impaired.

This study evaluates whether reflux function of the anal sphincter remains unchanged after restorative proctocolectomy, provided that the sphincter remaining is kept intact, without mucosal stripping or endo-anal anastomosis. Paired tests of anorectal function were performed before, and a median of 6 (range 2-12) months after restorative proctocolectomy with stapled, end to end pouch-anal anastomosis. Beforehand, distension of the rectum with 50 ml of air produced a median (interquartile range) increase in pressure within the rectum of 22 (15-29) cm H2O and reflex inhibition of the anal sphincter from a pressure of 76 (62-106) cm H2O to a pressure of 34 (15-52) cm H2O. After the procedure, distension of the ileal pouch with 50 ml of air produced an increase in pressure within the pouch of only 5 (4-8) cm H2O (p < 0.001 compared with beforehand) and reflex inhibition of the anal sphincter from a pressure of 62 (25-79) cm H2O to 37 (17-68) cm H2O. Maximal reflex inhibition of the upper third if the anal sphincter to a pressure of 26 (15-48) cm H2O was observed when pressure within the pouch increased by 16 (11-22) cm H2O. After restorative proctocolectomy, all patients were continent (two experienced minor nocturnal leakage of mucus) and 25 could discriminate between flatus and faeces. Thus, reflux function was preserved in response to changes in pressure, ensuring that the subtler aspects of anal continence were preserved.