As the “gold standard” for diagnosing intestinal diseases, colonoscopy is becoming more and more widely used, especially with the availability of painless anesthesia technology, which makes more people accept colonoscopy, so who needs this test? Or when you appear what symptoms need to perform colonoscopy? 1, chronic diarrhea or constipation Generally speaking, stool 1-3 times a day or 1-3 days a time, as long as the formation of regular even if it is normal, of course, it is best once a day. If the stool more than three times a day or more than three days only once, no regularity, and last for more than two months is called chronic diarrhea or constipation. At this time, you need a colonoscopy, the purpose is to exclude intestinal inflammation and tumor growth, if you can exclude, the doctor can diagnose functional intestinal disease, regulate intestinal function treatment can be. 2, blood in the stool Blood in the stool should not be ignored, many people first self-diagnose hemorrhoids, of course 90% of the blood in the stool is caused by hemorrhoids, but who can exclude themselves from 10% of it? So once there is blood in the stool, bright red or dark red, it is necessary to perform a colonoscopy, and only when intestinal lesions are ruled out, can you treat hemorrhoids with confidence. 3, difficult stool difficult stool is different from constipation, constipation is no bowel movement, difficult stool is bowel movement, that is, want to solve but can not be solved, this time the colonoscopy is necessary, many elderly people’s difficult stool because of intestinal lesions caused by local stenosis. 4, chronic abdominal pain chronic lower abdominal pain is mostly related to intestinal diseases, female patients should exclude gynecological diseases, intestinal inflammation and tumors can cause chronic abdominal pain, with vague pain and distension as the main manifestation, and diet sleep, stool situation, emotional impact is closely related. 5, the shape and regularity of the stool changes suddenly in the last three months, the shape of the stool changes, the regularity of the change should be highly concerned. 6.Self-examination of high-risk groups Immediate family members with colorectal cancer patients, frequent use of pickled products, spicy and stimulating foods, barbecue and other foods, and areas with high incidence of colorectal cancer in the nearby population are all high-risk groups, which should be self-examined by colonoscopy for early detection and intervention. In conclusion, there is no specific performance of colorectal disease, and the diagnosis cannot be confirmed based on symptoms or any laboratory tests. Minimally invasive treatment technology under colonoscopy is becoming more and more mature in China.