The prevention of the rectum and colon carcinoma consists principally in the radioendoscopic detection of colonic polyps. The double contrast enema is the best method for this detection. The usual practice of double contrast imposes the restatement of a comfortable method for the patient, simple and reliable for the doctor. The authors mean in this study to compare two groups of patients (group I and II) which differ by the double contrast technique used. If the colonic preparation, the injection implements and the investigation preliminaries are the same in both groups, there is no evacuation time of the barium enema which is added to trimebutine and stopped to the left iliac crest are specific with this method. The results allows an accuracy diagnosis of polyps.