Lactose intolerance is a non-infectious diarrhea caused by the body’s inability to completely digest and break down the lactose in breast milk or cow’s milk. You can determine whether your baby is lactose intolerant by checking the feces and observing the symptoms. 1. Examining the feces: You can examine the pH value of the feces to determine whether your baby is lactose intolerant. However, before conducting the stool pH test, the baby should be allowed to have normal breast milk or formula milk containing lactose, so that the degree of lactose absorption can be truly tested. 2. Observe the symptoms: baby lactose intolerance usually appears to diarrhea many times a day, often in the diaper a small amount of feces, most of the stool is yellow, greenish thin paste, eggdrop soup-like, with a lot of foam and milk, a few babies have anti-milk or vomiting phenomenon. At the same time, the baby is accompanied by abdominal distension and cries easily. In severe cases, dehydration and growth retardation may occur. As the baby lactose intolerance will cause certain impact on the health, so need to consult a doctor in time to diagnose and actively deal with.