Irritable bowel syndrome is a specific type of intestinal dysfunction that is considered to be related to visceral hypersensitivity, genetics, and emotional changes. Intestinal dysfunction refers to digestive tract syndromes with clinical manifestations without organic lesions, including functional dyspepsia, irritable bowel syndrome and functional constipation. 1. Functional dyspepsia: the main symptoms include postprandial fullness, epigastric pain and epigastric burning sensation. 2. Irritable Bowel Syndrome (IBS): a functional bowel disease characterized by abdominal pain or abdominal discomfort accompanied by changes in bowel habits. Abdominal pain is mainly in the lower abdomen and is often relieved after defecation. Diarrhea occurs in the morning or after meals, without blood. 3. Functional constipation: mainly caused by the weakening of peristalsis of gastrointestinal tract and uncoordinated movement of rectum and anal canal. Clinical manifestations of reduced frequency of defecation, defecation difficulties. The presence of irritable bowel syndrome needs to be examined under the guidance of a doctor, except for related organic lesions before diagnosis.