Before megacolon surgery, the intestines should be cleansed for more than one week. The purpose of cleansing the intestines is to remove the feces in the intestinal lumen, to avoid infections during the surgery, to improve the local inflammation, and to relieve the swelling of the intestines, which is conducive to the normal conduct of the surgery. Gastrointestinal preparation is needed before megacolon surgery, usually one week before the surgery, you need to perform a bowel cleansing, the intestinal residual feces and bacteria, etc., and need to be under the guidance of the doctor to preventive use of antibiotics, to avoid intraoperative infections. Generally in the week before the operation every day need to be enema, in about three days before the operation need to eat fluids, high protein diet, in the day of the operation can not eat, the specific norms of the preoperative preparations need to follow the doctor’s instructions. In the megacolon before surgery need to carry out positive preoperative preparation, patients need to actively cooperate with the doctor, keep calm, standardized preoperative preparation is conducive to the operation.