PURPOSE:The aim of this study was to determine the effect of eversion of the anorectum during restorative proctocolectomy (RP) for ulcerative colitis on functional outcome.METHODS:One hundred seventeen patients underwent RP with stapled end‐to‐end ileal pouch‐anal anastomosis (EEA), without resection of the anal mucosa. Sixty‐four underwent EEA with eversion of the anorectum, and 53 underwent EEA without eversion. Each patient underwent paired studies of anorectal function before and a median of 12 months after RP.RESULTS:One year after RP, median (interquartile range) maximum resting pressure was 69 (range, 51‐88) cmH2O in those patients who underwent eversionvs. 80 (range, 64‐90) cmH2O in patients without eversion(P(>0.04). Threshold sensation in the upper, middle, and lower thirds of the anal canal were 9.1, 7.4, and 6.8 mA after eversionvs.6.9, 4.9, and 3.8 mA without eversion(P=0.003,P<0.001,P<0.001, respectively). Before operation, all patients had a rectoanal inhibitory reflex; however, after RP, 54 of 64 patients in the eversion group and 50 of 53 patients with a stapled EEA without eversion had an inhibitory reflex(P=not significant). Leakage of mucus was experienced by 11 patients who underwent eversion, compared with 9 patients without eversion. Fifty‐six of 64 patients with eversion could defer defecation for more than 30 min compared with 43 of 53 patients without eversion. Twenty‐two of 64 patients in the eversion group retained perfect discrimination between flatus and feces compared with 38 of 54 without eversion(P<0.001). Level of the anastomosis was 1 (range, 0.5‐3) cm above dentate line after eversion compared with 1.5 (range, 0‐6) cm without eversion.CONCLUSION:Clinical outcome after RP with eversion was not as good as outcome after stapled EEA without eversion. Such a conclusion requires confirmation in a prospective control trial.