Doing colonoscopy drinking water regulations in doing colonoscopy 4-6 hours before drinking. Doing colonoscopy is usually 4-6 hours in advance to drink bowel cleansing medicine, while drinking about 2000mL of water, in small doses, it takes about 1-2 hours and back and forth, defecation, after taking the medicine, fasting, water until the colonoscopy. If you continue to drink, too much fluid in the bowel will affect the field of view. In addition, two days before the colonoscopy, you should pay attention to a light, less crumbly diet, do not eat green vegetables and fruits, but also do not eat red or seedy foods, such as watermelon, tomatoes, kiwi and so on. Lunch and dinner on the day before the examination should eat less residue, semi-liquid food, such as thin rice and noodles, so as not to affect the colonoscopy observation. Diet before doing colonoscopy should be strictly in accordance with the doctor’s instructions, if there is any discomfort after eating and drinking, you should consult a doctor in time.