PURPOSE: Low anterior resection, irrespective of anastomotic technique, may be associated with frequent bowel movement and other bowel management difficulties. The aim of this study was to access the anorectal function after low anterior resection of the rectal cancer. METHODS: We studied 28 patients who had mid and low rectal cancer (average 8.3 cm above the anal verge) had undergone low anterior resection using stapling suture devices (average level of anastomosis was 3.8 cm above anal verge) and anal manometry was undertaken 95 times preoperatively (N=28) and 3 month (N=26), 6 months (N=22) and 12 months (N=19) postoperatively from 1992 to 1995 in Korea University Guro Hospital. RESULTS: Maximum resting pressure was reduced after resection (from 64.7 mmHg to 42.7 mmHg, change ?22 mmHg) but gradually increased and returned to preoperative level at 12 months postoperatively. Minimum perceived volume was decreased after operation (from 40.3 ml to 25 ml change of ?15.3 ml) and this change persist at 12 months postoperatively. Rectoanal inhibitory reflex was present in all patient before surgery but disappeared in most of the patient after operation. Reflex returned to normal in 4 of 22 patients at 6 months later and in 7 of 19 patients at 12 months after operation. Maximum squeezing pressure and maximum tolerable volume were not decreased after operation. CONCLUSIONS: Anorectal function (maximum resting pressure, minimum perceived volume and rectoanal inhibitory reflex) was reduced immediately after low anterior resection of rectal cancer. But this functional changes returning to normal at 6 months and most of the patients had good function at 12 months after operation.