Ordinary gastroenteroscopy is only a diagnostic method, there is no obvious damage to the gastrointestinal tract, so there is no need to do coagulation function test. Gastroenteroscopy mainly examines the esophagus, stomach, duodenum, colon, rectum, etc. through gastroscope and enteroscope through the mouth or anus, and is able to determine whether there is any inflammation, ulceration, erosion, polyps, tumors, etc., in the mucosa of gastrointestinal tract. Gastroenteroscopy is usually performed using a long, thin, bendable medical instrument, about one centimeter in diameter, which is passed through the mouth or anus into the esophagus, stomach, duodenum, colon, rectum, etc. It allows the doctor to observe the internal condition of these areas and is a method of diagnosis that does not cause damage to the organs, and therefore does not require a coagulation test. Coagulation tests are required if gastroenteroscopy is performed. Drink plenty of water continuously before the gastroenteroscopy to promote bowel movements and to clean the intestines. Strictly follow the doctor’s instructions and be hospitalized if necessary.