The length of insertion for colonoscopy is variable depending on the location to be observed, and it is usually inserted 70-80cm to reach the ileocecal region or the end of the ileum. The main purpose of colonoscopy is to insert a flexible tube with a camera from the anus to the desired observation position to check whether there are inflammatory changes, intestinal polyps, intestinal tumors, etc. in the intestinal tract. The length of the insertion varies depending on the location of observation, but most of the time it reaches the end of the ileum or the ileocecal region, which is 70cm or 80cm. Usually, bowel preparation is required for colonoscopy, and fiber-rich fruits and vegetables are usually avoided the day before the examination. On the day of the examination, an oral laxative is usually taken to clean the bowel, and the examination can only be performed when the stool is clear and watery with no fecal matter, to avoid the influence of feces on the examination results. Patients who want to have a colonoscopy are advised to go to a regular hospital, consult with a professional doctor, and cooperate with the doctor to complete the relevant examinations to avoid blind treatment.