Piman is a spleen and stomach disease caused by the invasion of external evil, improper diet, phlegm and dampness obstruction, emotional disorder, spleen and stomach weakness, etc., which leads to spleen and stomach dysfunction, dysfunction of ascending and descending, and stagnation of stomach qi. The main clinical features are chest and abdominal distension, which are soft when pressed, painless when pressed, and no swelling when viewed. This syndrome can be divided into chest distension, subcardiac distension, etc. according to the location. Subcardia is the epigastric region, so subcardiac distension can also be called stomach distension. This section mainly discusses stomach distension. Stomach distension is a common syndrome among spleen and gastrointestinal diseases, and traditional Chinese medicine has a good effect in treating this disease. In Western medicine, chronic gastritis, gastric neurosis, gastroptosis, indigestion and other diseases, when the main manifestations are epigastric distension, fullness and discomfort, can refer to this section for syndrome differentiation and treatment.