The main symptoms of functional dyspepsia are abdominal distension, intestinal tinnitus, increased belching, and poor bowel movement. The main symptoms of functional dyspepsia are abdominal distension, intestinal rumbling, increased belching, and poor bowel movement. These factors can lead to excessive fermentation of food in the digestive tract and increased belching. Some belching is expelled physiologically through burping and venting, while other belching forms stagnation in the intestinal tract and causes increased flow of intestinal fluid and the sound of gas passing through water. However, many other digestive disorders can cause patients to have these adverse symptoms, such as chronic intestinal mucositis, chronic superficial gastritis, and intestinal flora disorders.