• Overall morbidity including infectious and non infectious complications [ Time Frame: peri operative ] [ Designated as safety issue: No ]
  

• - peri operative mortality - non infectious morbidity - anastomotic leakage - hospital stay - per operative evaluation of bowel preparation - clinical evaluation of bowel preparation [ Time Frame: 30 days, 6 months ] [ Designated as safety issue: No ]
  
• Evaluate the postoperative complications classified according to the DINDO classification. [ Time Frame: during the study ] [ Designated as safety issue: No ]
  

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.