Causes of bloating include diet, intestinal intolerance and other physiological factors as well as constipation, pelvic inflammatory disease and other gynecological diseases, intestinal diseases and other pathological factors. 1. Physiological factors: overeating and eating too much indigestible food can lead to bloating; eating lactose, fructose and other carbohydrates leads to intestinal intolerance, which can also lead to abdominal bloating; abdominal bloating and even diarrhea can occur during women’s menstruation. 3. Pathological factors (1) Constipation: constipation can cause poor exhaust, intestinal accumulation of gas can appear small abdominal distension. (2) Gynecological diseases: such as pelvic inflammatory disease, ovarian cysts, uterine fibroids and other gynecological diseases can appear symptoms of abdominal distension, and should go to the gynecologist. (3) Intestinal diseases: intestinal tumors can cause intestinal obstruction, resulting in small abdominal distension; small intestinal dyskinesia, intestinal flora imbalance and other diseases due to slow intestinal peristalsis can appear small abdominal distension. Small abdominal distension may also have other reasons, it is recommended to go to the hospital in time to improve the examination, under the guidance of professional physicians to clarify the cause of the disease, and give targeted treatment.