Doctors generally do not recommend that young people have colonoscopies. If a doctor does not recommend that a young person have a colonoscopy, it may be that there is no need for the young person to have a colonoscopy. When doing colonoscopy, the doctor needs to send the colonoscope into the intestines through the anus of the person being examined, and observe the specific situation in the intestines through the screen connected with the colonoscope, such as whether the color of the intestinal mucosa is normal, whether there are ulcers and other injuries, and whether the intestinal lumen is smooth, whether there are polyps, tumors and occupying lesions, and so on. In addition to regular medical checkups for high-risk groups, colonoscopy is commonly used for patients with certain suspected intestinal diseases, such as chronic diarrhea, some lower gastrointestinal bleeding, patients with colorectal polyps or tumors, as well as patients with abdominal masses that need to be ruled out for intestinal diseases. If a young person is advised by his or her doctor not to have a colonoscopy, it may be because the doctor does not consider the young person to have any of the above conditions and he or she may not have a family history of intestinal tumors, making a colonoscopy less necessary. If you have any abdominal discomfort or think of having a colonoscopy, you can take the initiative to inform your doctor, so as to avoid over-exertion of discomfort or delay of the condition by irregular treatment.