Tests that need to be done on an empty stomach mainly include biochemical tests, abdominal ultrasound and so on, and it is recommended that the patient be examined under the guidance of the doctor. 1. Abdominal examination: including abdominal ultrasound, cholangiography, due to eating will stimulate the gallbladder contraction and bile excretion, for the gallbladder exploration results will be inaccurate, and after eating the intestinal tract will have gas, will interfere with the exploration of other abdominal organs. 2. Biochemical tests: including liver function, renal function, blood lipids, blood glucose, electrolytes, etc., all of which need to be examined on an empty stomach in order to exclude the influence of eating on the test results and to avoid interference in clinical diagnosis. 3. Gastroenteroscopy: in addition to the requirement of fasting before the colonoscopy, but also for intestinal preparation, so as to avoid food and residual feces on the examination process and results caused by interference. In short, in order to ensure the accuracy of the test results, be sure to consult a doctor before the examination, test, follow the doctor’s instructions to make the relevant preparations.