Gastric retention is the retention of food residue and fluid in the stomach due to organic obstruction or functional lack of gastric tone. 1. A common organic disease is upper gastrointestinal obstruction due to peptic ulcer. Upper gastrointestinal obstruction is commonly caused by the healing of pyloric ulcers or duodenal bulb ulcers. The above ulcers are not treated properly, so the ulcers do not heal properly and scarring is formed, which leads to abnormalities in the structure of the gastric outlet, causing difficulty in emptying food from the stomach and leading to the occurrence of gastric retention. 2. If gastroscopy does not reveal any organic disease in the stomach and only gastric retention exists, then it should be considered that the gastric peristalsis is slowed down due to the lack of functional gastric tone, which causes retention in the stomach. Gastric retention is recommended to actively seek medical treatment under the guidance of a professional physician to avoid delaying the condition.