With the development of modern medical technology, endoscopy, as an extension of the doctor’s eye and hand, has reached the realm of “invisibility”. As far as the digestive system is concerned, there are: 1) electronic gastroscope that can complete the examination and treatment of the pharynx, esophagus, stomach and duodenum; 2) electronic enteroscope that can complete the examination and treatment of the entire large intestine and the 20 cm terminal ileum; 3) cholangioscope and duodenoscopic retrograde cholangiopancreatography (ERCP) that specialize in the examination and treatment of duodenal papilla, bile duct and pancreatic duct diseases; 4) capsule endoscope and small intestine microscope for small intestine 5. small probe ultrasound endoscopy, which can determine the depth of lesions, and endoscopic ultrasound, which integrates the examination and treatment of diseases of the gastrointestinal tract itself and nearby organs such as the pancreas; 6. laparoscopy, which can complete the direct examination and surgical treatment of organs in the abdominal cavity; 7. pigmented endoscopy, magnifying endoscopy, confocal endoscopy, narrow-band imaging and magnifying endoscopy for the early diagnosis of gastrointestinal tumors. endoscopy, etc. Through endoscopy, the following diseases can be diagnosed: 1. inflammation, ulcers, benign and malignant tumors occurring in the gastrointestinal tract (including esophagus, stomach, duodenum, small intestine and large intestine); 2. benign and malignant lesions in the ductal system of liver, bile and pancreas; 3. benign and malignant lesions in the abdominal organs. Compared with other imaging methods (such as gastrointestinal imaging, abdominal ultrasound, CT, MR nuclear medicine, etc.), endoscopic diagnosis has the obvious advantage of being able to take specimens for further pathological examination. There are many organs in the digestive system and a wide variety of diseases, so what are the signs of discomfort that require endoscopy? If the following digestive system symptoms occur, such as decreased appetite, difficulty swallowing, chest pain when swallowing, belching, acid reflux, heartburn, nausea, vomiting, vomiting blood, abdominal pain, abdominal distension, diarrhea, black stool, constipation, deformation of stool, blood in stool, alternating dry and loose stool, difficulty in defecation, weight loss, abdominal mass, etc., you should promptly undergo The corresponding examination should be done promptly. The contraindications of endoscopy are: 1, patients with critical or terminal disease; 2, patients with serious heart, brain and lung diseases who cannot tolerate the examination; 3, acute stage of gastrointestinal perforation; 4, patients with severe stenosis on the access to the mirror that prevents the access to the mirror; 5, patients with mental disorders who cannot cooperate. Early gastrointestinal tumors are often overlooked due to the lack of specific symptoms and signs. Endoscopic examination is necessary for clear diagnosis and early treatment of tumors in early stage. High-risk groups include: 1. Over 40 years old with one of the following conditions: loss of appetite, loss of interest in what you used to like to eat; weight loss for which no other reason can be found; abdominal discomfort and dull pain that comes and goes; bad gas; change in stool habit, mucus in stool, thin stool shape, dark stool; vomiting blood or history of bright red or dark red blood and mucus in the stool; urgency and heaviness that is Always feel that the stool is not finished; easy to have diarrhea and no other reasons can be found; unexplained positive fecal occult blood; 2. Having gastrointestinal cancer patients in the family, especially if there are gastrointestinal cancer patients in the immediate family; 3. Living or coming from areas with high incidence of stomach cancer. In China, places such as Liaodong Peninsula, Qixia County in Shandong Province, Changle County in Fujian Province and Wuwei County in Gansu Province are the high incidence areas of gastric cancer; 4. Pre-cancerous changes (such as chronic atrophic gastritis, gastrointestinal polyposis, residual stomach after gastric surgery, pernicious anemia and giant crepitations of gastric mucosa, i.e. Menetrer’s disease); 5. Masses felt in the abdomen; 6. Persistent or recurrent obstructive jaundice, the cause and nature of which cannot be determined by general examination Those who have diagnosed gastrointestinal tumor, in order to understand the type of tumor, the depth and scope of lesion, in order to decide the surgical plan. Regular review is also needed after gastric surgery in order to observe the changes of the disease. Generally speaking, high-risk groups must pay attention to receive regular gastroscopy and follow-up observation. The periodicity of the examination usually depends on the results of the last examination, and most of them are examined once a year. If you are in the upper high-risk group, you should have an endoscopy.