Before doing colonoscopy to pull yellow water without slag does not mean that the discharge is clean. Before the colonoscopy to pull yellow water, is not considered to be clear water, indicating that the contents of the intestinal tract has not been completely removed, at this time to carry out colonoscopy will affect the field of view of the mirror as well as the results of the examination. At present, the commonly used medicine to clean up the intestinal tract is polyethylene glycol powder, after taking the medicine, you should try to move back and forth, and gently rub the abdomen, many times when the bowel movement is watery, suggesting that it has been cleaned up. In the process of bowel cleansing may appear abdominal distension, abdominal pain, nausea, vomiting and other adverse reactions, the less severe symptoms can slow down the speed of drinking the drug, the more serious symptoms should immediately stop the bowel cleansing, and promptly to the regular hospital. It is recommended to follow the doctor’s advice to prepare for colonoscopy, otherwise it may affect the results of the examination, and even cause some damage to the body.