Many babies are currently intolerant to milk. Milk intolerance is due to lack of lactase, insufficient lactase activity or insufficient lactase secretion, which leads to the inability to completely break down the lactose in milk products, and the lactose that is not broken down will be broken down by the bacteria in the intestine into lactic acid, hydrogen, methane and carbon dioxide, which mainly manifests itself in the form of bloating, abdominal pain, epigastric discomfort, and even diarrhea after drinking milk. The main manifestation is that after drinking milk, the baby will experience bloating, abdominal pain, epigastric discomfort, or even diarrhea. In this case, the baby should not drink milk and should be fed non-dairy foods on the advice of a dietitian, while children under one year of age may have to consume milk substitutes. In addition, the trial of milk will be repeated every three months until the child no longer has an adverse reaction to milk, and then the amount of milk consumed can be gradually increased, so the mother does not need to worry too much.