Preoperative enema according to the different purposes of the operation, the steps and operation will be slightly different, the overall operation for a certain amount of solution through the anus, rectum, with the anal tube into the colon, to help the patient laxative exhaust, cleaning or treatment of disease. 1. According to the type of surgery and purpose of the preparation of the appropriate solution, commonly used in the clinic are soapy water, saline and so on. 2. The patient adopts the left lateral position, bending both knees to expose the buttocks, placing the enema solution in a high place, discharging the excess gas in the anal canal, and lubricating the anterior part of the anal canal with liquid paraffin. 3. After the lubrication work is completed, the anal tube is inserted into the rectum, the action is gentle not to hurt the mucous membrane, open the enema clamp, so that the liquid slowly flows into the rectum. 4. With the liquid into, some patients will have the intention to stool, at this time you can do a deep breath, the enema solution is properly lowered, so that the liquid is no longer downstream, you can move the anal tube, to avoid blockage of feces. 5. After the liquid filling is completed, close the enema clamp, wrap the anal tube with tissue paper and pull it out slowly. Preoperative enemas need to be performed by specialized doctors to avoid mucosal damage or emergencies.