1, colonoscopy for invasive examination, each hospital generally require preoperative examination of liver function and hepatitis B virus surface antigen, anti-AIDS antibody, anti-hepatitis C virus antibody (some hospitals check syphilis), as well as routine blood and so on. 2, enteroscopy from the anus and enter, check the rectum, sigmoid colon, descending colon, transverse colon, ascending colon, cecum, ileocecal valve; now advocate to enter the last section of the ileum. Do not check the small intestine or duodenum. 3, colonoscopy need to drink laxatives and water before the examination, in order to wash the colon, easy to observe the intestinal tract. Constipated patients should not eat a few days before the examination of crude fiber food to avoid producing more stool, if necessary, you can first take diarrhea medication. 4, enteroscopy due to inflation, the patient will feel bloating, whether the pain is determined by several factors: 1) the skills of the operating physician 2) the patient’s sensitivity to pain 3) the patient’s own condition: multiple laparotomy, pelvic surgery and so on. 4) Patient’s bowel alignment. People can add more. In general, individual patients may have pain in individual positions individual events, but generally can tolerate. 5) If you need detailed instruction, you can call for consultation.