There is no clear relationship between the time of day that a colonoscopy is performed; there is generally no difference between a colonoscopy done in the morning and one done in the afternoon. A colonoscopy is a procedure in which a flexible tube with a camera probe is passed through the anus into the bowel to see if there are any lesions in the bowel. It is difficult to see inside the bowel due to the feces obstructing the view, so a laxative enema is needed to empty the bowel before the colonoscopy is performed. As long as the bowel is emptied, the colonoscopy can be performed, so there is generally no difference in the effectiveness of the colonoscopy done in the morning or afternoon. Eat semi-liquid food such as thin porridge two days before the colonoscopy, and liquid food such as milk the day before, and fast on the day of the examination. After the colonoscopy should eat according to the doctor’s advice, avoid eating spicy and stimulating food after the operation. If you need to have a colonoscopy, it is recommended to consult a doctor in time and choose a suitable time under the arrangement of the doctor.