To clarify the pudendal sensory nerve(PSN)play in preventing fecal incontinence(FI)after low anterior resection(LAR) for lower rectal cancer, the PSN function was studied at 6 months after LAR. A total of 36 patients aged 42.0 to 79.0 years (23 males and 13 females with a mean age of 62.0 years)who underwent LAR for laparoscopic radical cystectomy(LRC) were enrolled in the present study. Based on postoperative F1, these patients were divided into 2 groups[group A; patients with FI(n=12), group B; patients without FI(continence, n=24)]. These were compared with group C(n=32, control subjects, 18 males and 14 females aged 40.0 to 76.0 years with a mean age of 61.8 years). Anal mucosal electric sensitivity (AMES)threshold was measured [at the upper 1 cm oral side from dentate line(DL); a, DL; b, and lower zones 1 cm anal side from DL; c]. FI after LAR was also evaluated by the Wexner score(WS). All patients were pathological Stage Ⅰ(25 patients: T1, N0, M0; 11 patients: T2, N0, M0). Group A had a significantly larger proportion of males than group B(p< 0.05). The distance of anastomosis from anal verge(DAAV)in group A(2.4±1.8 cm)was significantly shorter than in group B(4.4±0.9 cm)(p<0.001). WS from 6 to 10 comprised 25.0% of group A, 11 to 15 comprised 50.0%, and 16 to 20 comprised 25.0%. All patients in group A(WS; 8 or more)were incontinent. In contrast, all patients in group B(WS; 0) and C(WS; 0)were continent. Patients in pre-operative defecation(WS; 0)were also continent. On the AMES(a, b, c), sensitivity of patients in group A(6.4±1.1, 5.1±0.5, 4.9±0.6 mA)was significantly higher than in groups B(2.6±0.5, 2.4 ±0.4, 2.5±0.6 mA)and C(2.3±0.4, 2.1±0.4, 2.3±0.5 mA)at all zones(p<0.001). FI after LAR with a short DAAV, especially male, may be PSN dysfunction due to operative damage of PSN.