Many people have symptoms such as stomach pain, bloating, acid reflux, heartburn, abdominal pain, bloating, diarrhea and even constipation and blood in the stool. The most common causes of these symptoms are gastritis, gastroduodenal ulcer, gastric cancer, esophageal cancer as well as colitis, colon polyps and colon cancer, among which inflammation or polyps are benign lesions and can be treated well, while gastric cancer, esophageal cancer and colon cancer are malignant tumors and only early diagnosis and early treatment can be effective. The most accurate and intuitive method for early detection of these diseases is gastroscopy and colonoscopy. However, many people are reluctant to take the initiative to do gastroscopy or colonoscopy, for one reason, they are too troublesome, and for another, they feel uncomfortable during the examination. This leads to the development of the disease to the middle and late stage of cancer and misses the best time for treatment. Under what circumstances should gastroscopy be done? Those who have upper gastrointestinal symptoms, suspected esophageal, gastric and duodenal lesions and need to be diagnosed clinically; those with unexplained gastrointestinal bleeding; those whose nature of lesions cannot be determined by barium X-ray examination; those who have diagnosed upper gastrointestinal lesions such as ulcer, chronic gastritis, gastric precancerous lesions, etc. and need gastroscopy follow-up review; those who suspect foreign bodies in the upper gastrointestinal tract; those who have family history of gastric cancer and need gastroscopy; those who have H. pylori infection Those who need to clarify the gastric mucosal lesions or those who need H. pylori culture to guide the treatment. Since there are no obvious symptoms in the early stage of gastric cancer, gastroscopy is the best method for early gastric cancer. For people aged 40~50 years or above with risk factors for gastric cancer, such as family history, positive H. pylori, previous gastric ulcer and atrophic gastritis, gastroscopy is recommended once every 1-3 years. Those who are over 30 years old, have lower gastrointestinal symptoms such as blood in stool, irregular stools, family history of colorectal cancer, those who have had colon cancer, polyps or have schistosomiasis, ulcerative colitis and other diseases should have regular colonoscopy. people over 40 years old, both men and women, should have regular medical checkups and stool occult blood test every year regardless of whether they have symptoms or diseases. people over 50 years old who have not had colonoscopy Or those who have a family history of colon tumor over 40 years old are recommended to undergo colonoscopy. The detection of early cancer and precancerous lesions can greatly reduce the incidence of colorectal cancer and improve the survival rate and quality of life of patients. Some people have concerns about doing colonoscopy and feel that there is no need to review it every year, which is bothersome and uncomfortable. In fact, gastroscopy and colonoscopy do not need to be done every year. Those who have no obvious abnormality after gastroscopy can be reviewed after 3 years; those who have no obvious abnormality after colonoscopy can be reviewed after 5 years. Gastroscopy, esophageal cancer and colon cancer account for about 1/3 of all malignant tumors in China, and timely gastroscopy can reduce the risk of death from such malignant tumors by about 1/3.