It is not enough to drink 1000ml electrolyte water for colonoscopy, about 3000ml electrolyte water. The commonly used laxative for colonoscopy is compounded polyethylene glycol electrolyte bulk, if it is electrolyte bulk containing A and B powder, usually a box of powder contains 6 bags of A and 6 bags of B. 750ml of water is needed to flush a box. Generally 4 boxes are prescribed, i.e. 3000ml of water is required for complete flushing. Therefore a single colonoscopy will require roughly 3000ml of electrolyte water. If other types of electrolyte dispersions are used, they need to be taken as prescribed by the doctor, and generally how much electrolyte water to drink is also based on the patient’s own condition. Patients with fast emptying only need about 2000ml of electrolyte water, while patients with slow emptying may need about 3500ml of electrolyte water. Drinking can be facilitated by massage, etc., generally until the stool is watery. In conclusion, 1000ml of electrolyte water for colonoscopy is not enough, patients should take electrolyte water under the guidance of the doctor and in conjunction with their own situation.