A colonoscopy is the insertion of an examining scope with a lens through the anus, through which the presence of intestinal abnormalities is examined. Colonoscopy can be divided into normal colonoscopy and painless colonoscopy, and the difference between the two is whether or not anesthesia is required before the colonoscopy is performed. The day before the colonoscopy, you should not eat fiber-rich food, and on the day of the examination, it is better to fast and prepare the bowel until the stool is clear water or light yellow without fecal sludge, and then you can carry out the examination, and the purpose of cleansing the intestines is to prevent obstruction of the field of vision in the examination process. If the patient has no way to cooperate with the examination or is highly nervous, painless colonoscopy can be chosen. After the colonoscopy, follow the doctor’s instructions to eat.