Babies always have diarrhea usually take into account the following situations: 1. The most common cause of diarrhea in infancy is food allergy, including milk protein allergy, egg allergy, etc. If breastfeeding is also related to the mother’s diet, if the mother ingests food that is easily allergic, the baby will have digestive symptoms that are prone to recurrent episodes. 2. The baby may have a poorly established intestinal micro-ecosystem, especially before the age of 2 years, which is susceptible to imbalance in the micro-ecosystem due to the external environment and infectious factors, and is prone to poor digestion and absorption, and always has diarrhea. 3. The pathogenic force is not strong but more stubborn also prone to always diarrhea.