Postoperative ileus (POI) causes patient's discomfort and leads to an increase of cost of management after colorectal surgery because of an increase of the morbidity rate or of the rate of early rehospitalization after discharge.

Enhanced recovery programs allowed a reduction of its rate but 20 to 30% of patients will experiment POI.

A new approach during preoperative era, using mastication or preoperative physical activity, has been proposed to improve postoperative course. This leads to a vagal activation (action especially on upper GI).

Sacral stimulation using percutaneous tibial nerve stimulation (PTNS) has an effect on lower GI.

The aim of this study was to assess the efficacy and the feasibility of PTNS during perioperative course, to prevent POI with respect with placebo.

Inclusion Criteria:

• patients > 18 years
• elective colectomy or proctectomy
• agreement for the research

Exclusion Criteria:

• chronic inflammatory bowel disease
• irritable bowel disease documented
• history of surgery on oesophagus or stomach
• acetylcholine dysfunction
• enterostoma
• patient holder of pace-maker