The main manifestations of lactose intolerance include abdominal distension, diarrhea, nausea, vomiting, hyperactive bowel sounds and colic, etc. Some patients may experience constipation due to weakened intestinal motility. Symptoms of lactose intolerance, the severity is related to the amount of dairy products eaten, young children with lactose intolerance, the common symptoms are diarrhea, typical stools are yellow loose stools or eggdrop soup Yang, with foam and sour smell, there will be milk lumps in the stools, a small number of infants and young children will be back to the milk and the phenomenon of vomiting. Lactose intolerance, also known as lactose malabsorption or lactose indigestion, refers to the fact that the human body does not produce the enzyme lactase, which breaks down lactose, and therefore is unable to fully digest the lactose in dairy products, and the symptoms of lactose intolerance will appear after eating or drinking dairy products.