Recovery of the rectoanal inhibitory reflex after restorative proctocolectomy: Does it correlate with nocturnal continence?

PURPOSE: The rectoanal inhibitory reflex has an important role in fecal sampling and discrimination of rectal contents. The aim of this study was to determine the significance of rectoanal inhibitory reflex after restorative proctocolectomy with ileal pouch-anal anastomosis for mucosal ulcerative colitis. METHODS: The medical records of 345 patients who underwent ileal pouch-anal anastomosis from September 1988 to May 1999 were retrospectively reviewed. One hundred patients who underwent double-stapled ileal pouch-anal anastomosis and had anorectal physiology testing within 3 months before surgery as well as after ileostomy closure (mean, 23.1; range, 3-77 months) were analyzed. Anorectal physiology testing included detecting the presence of the rectoanal inhibitory reflex, sensory threshold volume, and rectal or pouch capacity and compliance. Parameters to determine incontinence included daytime and nocturnal bowel movement frequency, nocturnal spotting, status of continence for solid or liquid stool, gas, use of pads, and lifestyle alteration were surveyed in 62 of the 100 patients at a mean of 3.9 (range, 1-9.1) years to determine the incontinence score. RESULTS: Whereas the rectoanal inhibitory reflex was noted in 96 (96 percent) patients before surgery, it was found in only 53 (53 percent) after ileostomy closure (P < 0.0001). Incontinence status data was available in only 62 of the 100 patients (32 RAIR-positive; 30 RAIR-negative). There were no significant differences between the rectoanal inhibitory reflex-positive and the rectoanal inhibitory reflex-negative groups relative to the interval between surgery and manometry (22 vs. 25 months), postoperative threshold sensation volume (32 vs. 31 ml), postoperative compliance (19 vs. 12 cm H₂O/ml), postoperative capacity (85 vs. 66 ml), daytime/nighttime stool frequency (6.2/2 vs. 5.5/1.5), or postoperative incontinence score (3.9 vs. 1.8). However, there were significant differences relative to the incidence of nocturnal soiling (12/30 (40 percent) vs. 23/32 (72 percent), P = 0.0012) favoring the presence of the rectoanal inhibitory reflex. CONCLUSION: Preservation of the rectoanal inhibitory reflex correlated with a decrease in the incidence of nocturnal soiling after double-stapled ileoanal reservoir construction.