Gastroenteroscopy can directly observe inflammatory lesions such as congestion and edema of the mucosa of the gastrointestinal tract through gastroscopy and enteroscopy, and can also detect lesions such as polyps and tumors. If gastroenteroscopy finds congestion, edema, erosion, etc. in the mucosa of the gastrointestinal tract, it usually suggests mucosal lesions, which may be inflammatory diseases such as gastritis, gastric ulcer, enteritis, and so on. If the examination finds that the mucosal surface appears spherical, mound-shaped, ovoid and other superfluous organisms, the surface is smooth, not easy to bleed on touch and relatively soft, may be intestinal polyps. If the examination finds that the mucosa of the gastrointestinal tract has multiple erosions, swelling, bleeding, etc., the surface is uneven, and part of the mucosa is hardened and feels stiff when touched, this may be gastric cancer, intestinal cancer and other diseases. Gastroenteroscopy should be prohibited in case of acute attack of gastrointestinal perforation, heart failure, psychiatric patients and so on. Gastroenteroscopy should not be performed during pregnancy and in infants and young children. Gastroenteroscopy can detect mucosal lesions, which is conducive to the diagnosis and treatment of digestive tract diseases. Gastroenteroscopy should be performed under the guidance of a professional doctor and in conjunction with other symptoms and examinations to make a comprehensive judgment of the condition.