Mechanical aspiration of intestinal contents has been utilized in colon surgery for decades without scientific proof of the benefits of the procedure. According to randomized studies performed on the subject, mechanical cleaning of the bowel before surgical operations of the colon is unnecessary and even harmful to the patient. Intestinal operations must be carried out applying careful surgical aseptic techniques and appropriate antibiotic prophylaxis, and it is recommendable to abandon the routine emptying in surgical operations of the large intestine.