Painless colonoscopy is widely welcomed by patients as it spares them the discomfort of bowel movements caused by insertion of the scope, bloating caused by inflation, abdominal pain and nausea caused by pulling on the intestinal wall. But there are two sides to everything, pain is actually a protective mechanism to avoid greater harm, imagine, a person without pain, hand holding a soldering iron until the hand burns will not let go. Patients in the awake time, if we inflate too much, intestinal tube overstretching, enteroscopy up climb and other cases patients will cry abdominal distension and abdominal pain, we will be timely aspiration, push the mirror, unclimbing, the operation of the doctor’s gestures will be alleviated or even suspended, but in the patient was anesthetized without the patient’s communication, endoscopy doctor may gas will be more inflated, will slip the mirror, will be in the case of the belt climb to continue to insert the mirror, which will increase the risk of intestinal perforation, or the mesentery is overstretched, or the mesentery is overstretched. This will increase the risk of intestinal perforation or excessive pulling of the mesentery leading to mesenteric injury. According to the feedback from endoscopists in major hospitals, since painless enteroscopy has been widely carried out, there has been a significant increase in ischemic enteropathy caused by enteroscopy, which is generally manifested as abdominal pain, diarrhea and blood in the stools about one week after painless enteroscopy, especially small enteroscopy; and again enteroscopy manifests as intestinal mucosal edema, submucosal hemorrhage, and part of necrotic and ulcerated mucosa, and so on. This is because painless enteroscopy when the patient can not give the doctor harmful information feedback, the patient’s intestinal curvature is large, the doctor’s gesture is heavy, resulting in excessive pulling of the mesentery caused by mesenteric vascular injury, resulting in intestinal ischemia. Therefore, painless colonoscopy should not be used excessively, of course, the doctor’s gesture gently, the degree of skill is also very relevant. So we need to remind: 1, even if it is painless colonoscopy, the patient will not cry out in pain, and the operating doctor will give as little gas as possible, operate under the clear vision, operate gently, and do not bring climbing into the mirror. 2, painless colonoscopy after the end of the patient if the abdominal pain is difficult to remain, to think of the possibility of intestinal perforation, emergency abdominal radiographs, can not carelessly cause infectious shock and other more serious consequences.