Lactose intolerance in infants can be initially determined by clinical symptoms, which mainly include flatulence, diarrhea and other undesirable symptoms, and the specific situation requires timely medical examination. Lactose intolerance in infants usually refers to the lack of lactase enzyme in the body, and the identification of infants suffering from such a disease can be based on clinical symptoms for initial judgment. After consuming breast milk or cow’s milk and other dairy products, infants may experience flatulence, diarrhea, nausea, vomiting and other symptoms, and the frequency of stools may increase significantly, and persistent diarrhea may cause dehydration. In addition, infants with lactose intolerance may also experience colic, which may be characterized by prolonged crying. Lactose intolerance in infants also affects absorption, making them prone to malnutrition, which can have an impact on growth and development. When such symptoms occur, it is necessary to consult a doctor for examination, and according to the results of the examination, choose the appropriate treatment under the guidance of the doctor.