The aim of this controlled multicentric study is to assess rectal cancer surgery with sphincter preservation without pre operative mechanical bowel preparation

Preoperative mechanical bowel preparation (MBP) (i.e. including oral laxatives, retrograde enemas and/or oral diet before surgery) is the standard practice in colorectal surgery. The importance of MBP in preventing anastomotic leakage and infectious morbidity after elective colorectal surgery has been a dogma among surgeons for many years. The main reason is the belief that postoperative complications is related to septic bowel content. However, there is a paucity of scientific evidence demonstrating the efficacy of this practice in reducing morbidity. Moreover, potential disadvantages of MBP include the requirement for a longer preoperative duration of admission before surgery, its time consuming nature, being expensive and unpleasant for the patient and expose the early population to the particular risk of fluid and electrolyte imbalance .At least eight randomized clinical trials and two meta-analyses failed to show any superiority of MBP in colorectal surgery. On the contrary, they demonstrated that preparation might lead to an increased rate of septic complications. Such initial dates lead surgeons to re-evaluate their current clinical practice in colonic surgery. But to dates, these findings cannot finally be applied to rectal surgery because of insufficient dates. To date, no study about MBP was specifically devoted to rectal surgery. Moreover, it is currently admitted that the risk of septic complications following rectal resection, as a result of the well-known risk factors, is higher than after colonic preparation. It is the reason why most of the colorectal surgeons consider that a no preparation regimen in rectal cancer surgery could represent an additive risk factor for postoperative morbidity.

Inclusion Criteria:

• Age > 18 years
• patient with rectal cancer without any metastasesRectal excision with sphincter preservation with colorectal or coloanal anastomosis (with or without temporary ileostomy)

Exclusion Criteria:

• Stage IV disease
• Comorbidity with post operative infectious risk corticoids,immunodeficiency, Crohn's disease, ulcerative colitis ...)
• Abdominoperineal resection
• Emergency surgery