Electrolyte water for gastroenteroscopy does not have to be drunk within 2 hours, it should be adjusted according to the patient’s own state, and the specific time needs to be adjusted according to the doctor’s instructions. 1. The electrolyte water for gastroenteroscopy is polyethylene glycol electrolyte, the dosage is about two thousand milliliters after blending with water, and the total amount is not more than four thousand milliliters, and the dosage should be adjusted according to the patient’s disease condition, physical condition and body weight. Polyethylene Glycol Electrolyte achieves bowel cleansing effect through hypertonic environment in the intestinal tract. 2. Patients can drink at an appropriate speed according to their condition and decelerate the dosage when the bowel movement becomes clear liquid. The time of the first bowel movement is usually about one hour after taking the medicine. It is recommended that patients follow the doctor’s instructions to take the medicine, patients can do gastroenteroscopy 2 days before a low residue semi-fluid diet, the first day of a full-fluid diet without residue, the day of the examination should be fasting and water fasting for 4 to 6 hours.