For a colonoscopy, 200 ml of water mixed with the medicine is required to be taken within 5 minutes, and about 2 liters of water is to be drunk within 2 hours of taking the medicine. Start taking the bowel cleansing medication 4 to 5 hours before the colonoscopy by mixing 200 ml of water with the medication and then taking it within 5 minutes. Within 2 hours of taking the medicine, continue to drink about 2 liters of water, which can be divided into several times, but pay attention to the speed of drinking, not too fast and not too slow, to avoid affecting the effect of bowel cleansing. If some patients have achieved bowel cleansing after drinking 2 liters of water, then the dose can be stopped. However, some patients may have a poorer intestinal cleansing effect after drinking 2 liters of water and need to increase the amount of water they drink. When patients drink less water, it may lead to incomplete excretion of stools, and excessive fecal residue left in the intestines will cover the intestinal lumen when performing colonoscopy, which will affect observation and produce a large number of blind spots. It is recommended that in the process of drinking water, more stomach rubbing, more walking to help defecation, the intestinal tract can be cleaned after the colonoscopy, the specific precautions before the colonoscopy should be strictly follow the doctor’s instructions.