In general, if a doctor does not recommend lactase, it is probably not necessary to use lactase itself. Lactase is an active enzyme produced by the human body, which can break down lactose in the digestive tract into galactose and glucose to improve the discomfort of bloating and diarrhea caused by lactose malabsorption, and can also promote immunity and enhance appetite to a certain extent, and is often used in clinical diarrhea patients. Because it is a substance that can be produced by the body itself, it is safe and can be used safely by infants and children, in addition to having a positive effect. Lactose intolerance is due to the lack of lactase in the body, the lactose intake cannot be absorbed, when the intake of milk and breast milk containing high lactose, lactose can not be decomposed and absorbed, the patient can appear intestinal tinnitus, bloating, acute abdominal pain, diarrhea and other symptoms, to be lactase is a more ideal alternative treatment method. However, if the diarrhea or indigestion is not itself caused by lactose intolerance, then lactase has no effect on the symptoms, and therefore doctors do not recommend it.