Gastroscope generally refers to gastroscope. Gastroscope and enteroscope have the same construction, but the length and thickness of the mirror are different, the preparation before doing the examination is also different, and the observation sites of both are also different. Because the intestinal tract of the human body is longer, the mirror of enteroscopy is a little longer and thicker than that of gastroscopy. Gastroscopy is operated from the mouth or nasal cavity through the throat into the stomach, mainly used to observe the stomach and duodenal mucosa, while colonoscopy is from the anus into the body to check the large intestine, mainly used to observe the mucosa of the rectum and colon. Gastroscopy requires 6-8 hours of fasting and no bowel preparation other than fasting, while colonoscopy requires 8-10 hours of fasting and a laxative to expel secretions for bowel preparation. The choice between colonoscopy and gastroscopy needs to be based on the patient’s specific situation and the judgment of the specialist, and the examination should be performed with adequate preparation.