BACKGROUND/AIMS: Unsatisfactory functional results have been reported not only after coloanal anastomosis, but also after anterior resection with colorectal anastomosis. The aim of this study is to establish functional outcome predictive factors related to surgical technique and especially the real impact of residual rectum length to identify patients who could benefit from colonic pouch reconstruction. METHODOLOGY: Sphincter preservation was achieved in 214 of 327 patients who underwent surgery for rectal cancer. Patients have been subdivided according to the level of anastomosis measured by a rigid proctoscope from the anal verge. In 93 patients functional results have been assessed by clinical control and anorectal manometry. RESULTS: Functional alterations such as leakage (13%), incontinence (5%), urgency (5%) and difficulty in evacuation (10%) appeared in patients who underwent anterior resection with anastomosis 4 to 6 cm from the anal verge. Nevertheless, comparing anterior resection with anastomosis 6 to 8 cm and that with anastomosis 4 to 6 cm rectal compliance was the only parameter whose difference is statistically significant. CONCLUSIONS: This result makes us to believe that patients who undergo anterior resection with no more than 2-3 cm of residual rectum could benefit from a colonic pouch reconstruction
