Patients with gastroenteritis can be tested in the following ways: 1. Serological examination, by taking blood samples from patients and counting cells such as leukocytes and eosinophils in the serum, a preliminary diagnosis of the presence of inflammatory diseases can be made. This is because the infection of the gastrointestinal tract by sensitive bacteria will cause the human immune system to have a specific immune response and cause the symptoms of an increase in the number of phagocytes in the body. 2. fecal culture examination, by taking samples of the patient’s fecal matter and smearing them, the harmful microorganisms such as bacteria, viruses and parasites can be investigated and detected. 3. gastrointestinal microscopy, gastrointestinal microscopy, in addition to in vivo sampling The gastroscopy not only diagnoses the type of disease of the patient by means of biopsy, but also makes pathological observation of the size, shape, location and other information of the diseased tissues, which has an important reference role for the formulation of subsequent treatment plans.