All patients suffering from a postoperative small bowel obstruction will be included in this study. They will be randomised in 2 groups. In group S, patients will have CT-Scan and oral water administration while in group SG, Patients will have CT-Scan and oral gastrografin administration The major end point of this study is to analyse whether imaging examination can reduce the need for a surgical approach or the rate of small bowel resection and to determine its influence on fasting time or hospitalization duration