Painless colonoscopy can eliminate patients’ nervousness and anxiety and improve their tolerance to the examination; patients have no memory and painful feeling for the whole examination process; at the same time, gastrointestinal peristalsis is reduced, which facilitates the discovery of microscopic lesions; it also reduces the occurrence of mechanical injuries caused by unconscious agitation of patients due to pain. Painless endoscopy differs from ordinary endoscopy in that all acute gastrointestinal bleeding, severe snoring and severe intestinal adhesions are contraindications to the examination. After completion of painless endoscopy, patients should be fully awake and accompanied by relatives before going home, and should not drive, engage in mechanical work or work requiring calculation and logical analysis within 24 hours. Transnasal gastroscopy Transnasal gastroscopy is characterized by a very thin and very flexible diameter. Entering the digestive tract through the nasal cavity reduces the irritation to the throat and the pulling effect on the stomach wall is weak, which can greatly reduce the patient’s discomfort and pain during the gastroscopy. Adequate nasal mucosal anesthesia can make patients feel no discomfort in the nasal cavity. It can be said that the transnasal gastroscopy technique is a “comfort gastroscopy” technique close to painless gastroscopy. Patients can talk with the physician during the examination, so that the examination can be completed in a relaxed and pleasant environment.