The price of abdominal plain film varies from place to place, about 90 RMB in Shanghai (please refer to the price published by the price bureau of each place). The main purpose of abdominal plain film is to find out whether there is obvious pneumatization of the intestinal canal in the abdominal cavity, or whether there is a gas-liquid plane to see whether there are signs of intestinal obstruction. In addition, abdominal plain film can also look at whether there is free gas under the diaphragm, which can clarify whether there is the possibility of perforation of the digestive tract. If the patient’s clinical symptoms are serious and the abdominal plain film does not indicate any abnormality, the doctor will recommend further CT examination of the abdomen to clarify whether there are clear lesions around the abdominal organs and intestinal canal.