There are many reasons why the stomach becomes bigger, which are commonly found in obesity, intestinal obstruction, abdominal fluid accumulation, ovarian cysts in women and so on. 1. Obesity: due to the lack of good living habits, overeating, lack of exercise, etc., so that the accumulation of fat in the abdomen, resulting in a larger stomach. 2. Intestinal obstruction: intestinal contents cannot run normally and pass through the intestines smoothly, and are retained in the intestines, resulting in paralysis of the intestinal muscles and excessive gas production of the intestinal contents, causing abdominal distension, which can also result in a larger stomach. 3. Abdominal fluid accumulation: such as cirrhosis, portal hypertension can lead to accumulation of fluid in the abdominal cavity, resulting in stomach enlargement. 4. Ovarian cysts: Abdominal masses, especially large cysts in the abdominal cavity, such as ovarian cysts in women, can also lead to an enlarged stomach. The enlarged stomach may also be related to other causes, such as splenomegaly, etc. If accompanied by abdominal discomfort, it is recommended to consult a doctor in time to clarify the cause of the disease under the guidance of a medical professional.