To examine the duodenum, an electronic gastroscope is needed. The scope of the electronic gastroscope is from the entrance of the esophagus to the descending section of the duodenum, and most of the lesions of the duodenum occur in the bulb of the duodenum, so to examine whether there are lesions in the duodenum, an electronic gastroscope is needed. The often said electronic colonoscopy refers to the electronic colonoscopy, which mainly examines the parts of the colon, as well as the rectum. There is also a small colonoscopy for the small intestine, but the operation of small colonoscopy is very complicated, so most hospitals do not carry out. There is also a capsule endoscopy method that allows the entire gastrointestinal tract to be viewed, but it is mainly through computerized picture capture, so the accuracy may be lower compared to the manually operated electronic gastroscopy e-colonoscopy. If patients want to view the duodenum they need to do an electronic gastroscopy, not a colonoscopy.