In the morning of the day when patients do colonoscopy, they should take two bags of polyethylene glycol sodium potassium bulk orally with 2000~3000 ml of warm water. In addition, it should be noted that patients should eat mainly fluids, such as porridge, boiled vegetables, etc. three days before the colonoscopy, do not eat spicy stimulation, too greasy, rough and indigestible food. When patients take polyethylene glycol sodium potassium powder, you can walk around while drinking and gently massage the abdomen with your hand to help discharge the stool. Polyethylene glycol sodium potassium powder has a flushing effect on the intestinal tract, patients take the drug is not absorbed, the hypertonic solution in the intestinal tract so that the intestinal tract can not absorb the water, the water in the colon lumen to make the stool. However, the use of Polyethylene Glycol Sodium Potassium Disodium is prohibited if the patient has intestinal perforation, intestinal obstruction, or severe inflammation of the intestines caused by the function or structure of the intestines.