Abdominal pain mainly refers to symptoms such as abdominal pain and bloating. Abdominal pain refers to pain in the abdomen due to lesions of internal and external organs caused by various reasons. It is commonly seen in chronic lesions of the stomach, liver, gallbladder, pancreas and spleen. If the clinical diagnosis of the disease causing the abdominal pain is uncertain, the abdominal pain can be investigated as a preliminary diagnosis and treated with evidence. In addition to the main manifestation of epigastric distention and fullness in the upper abdomen with recurrent episodes for more than 2 months, which may be accompanied by reduced diet, belching and abnormal stools, the following ancillary tests should be performed. Examination: Abnormalities in fiberoptic gastroscopy, upper gastrointestinal X-ray, gastric fluid analysis, etc. can help in the diagnosis of celiac disease. A fiberoptic gastroscope is a gastroscope made of light-guided glass fiber bundles that is inserted through the mouth into the stomach through the esophagus. It has the advantages of soft and bendable, cold light source, clear peep, direct and safe operation. The maximum gastric acid secretion measurement (MAO) introduces the amount of gastric acid that can be secreted by the lining cells after stimulation by pentagastrin for 1 hour to fully utilize their secretory function, which is called MAO.