Assessments of Anal Canal Sensitivity in Patients with Soiling 5 Years or More after Colectomy, Mucosal Proctectomy, and Ileal J Pouch‐Anal Anastomosis for Ulcerative Colitis

Abstract

To clarify the significance of anal canal sensitivity contribution to soiling in patients after ileal J pouch-anal anastomosis (IPAA) for ulcerative colitis (UC), we studied the sensory function of the anal canal. Forty patients with UC who had undergone IPAA with ileostomy closure at least 60 to 132 months (mean 103.6 months) previously, and who had no preoperative or postoperative complications were recruited. They were divided into two groups: group A [n = 26; patients without soiling (16 males, 10 females; ages 15-49 years, mean 36.6 years)] and group B [n = 14; patients with soiling (10 men, 4 women; ages 24-56 years, mean 40.9 years)] compared with group C [n = 28; control subjects (18 men, 10 women; aged 19-49 years, mean 38.5 years)]. Patients with soiling were also divided into three groups (B1, rare soiling; B2, occasional soiling; B3, frequent soiling). The anal canal sensitivity threshold was measured using an anal canal electrosensitivity test (ACEST). The measurement point of anal canal was divided into three parts: lower part [1 cm below the dentate line (DL), middle part (just on the DL), and upper part (1 cm above the DL]. A small electric current from a constant-current generator was passed between the electrodes until the patient felt a sensation often described as tingling or pulsing. The threshold of sensitivity was assessed in the upper, middle, and lower parts of the anal canal. In patients of group C, recording at the middle part of the anal canal showed the best results. The anal canal sensitivity threshold of group B was significantly higher than those of groups A and C at the upper and middle parts (P < 0.0001, respectively). There were no significant differences at the lower part among groups. The anal canal sensitivity threshold of subgroup B3 was significantly higher than those of groups B1 or B2 at both the upper part (P = 0.0002, P = 0.0038, respectively) and middle part (P = 0.0001, P = 0.0480, respectively). There were no significant differences at the lower part among groups. The ACEST shows significantly lower sensitivity in the proximal and middle anal canal in IPAA patients with soiling.