Generally, if the subject has no other abnormalities, he or she can resume eating 2 hours after undergoing the colonoscopy. During the colonoscopy, a thin, flexible tube is inserted through the anus into the rectum and advanced to the other end of the large intestine to transmit images of the internal structure of the intestine and to observe the presence of abnormalities. Therefore, during the examination, the tubular instrument may cause irritation to the local surface mucosal tissue of the intestine, especially during biopsy, and may even cause traumatic injury, resulting in postoperative adverse effects such as abdominal pain, bloating, and bloody stools. Therefore, the patient should avoid eating for 2 hours after undergoing colonoscopy to avoid aggravating the degree of adverse symptoms. In addition, when eating is resumed after the colonoscopy, the structure of the diet should be mainly liquid, low residue, light and other types of food to reduce the irritation to the intestinal tissues. If, after the examination, the patient develops severe or persistent abdominal pain, blood in the stool and other symptoms, it is also necessary to promptly follow up the examination.