The structure of breastmilk is best suited for a baby’s digestive system. Therefore, under normal circumstances, babies will not have diarrhea on breast milk. When this situation occurs, first of all, we should consider several factors. First, whether there is a problem with the breastmilk, breastmilk problems are mainly the following aspects. 1, the mother’s recent physical state, emotional have no abnormalities. If there is severe anxiety or emotional changes, or lack of sleep, it may lead to abnormalities in the composition within the milk.2. Whether the mother has recently suffered from mastitis. If there is mastitis, then it can lead to inflammation of the baby’s intestines by secondary infection. Secondly, excluding the factors of breast milk, the baby’s own factors also have a certain impact, such as whether the development of the baby’s intestines is normal or not, and whether the baby has recently been infected by the intestinal flora and develops enterocolitis, if there is the existence of these problems, then it is necessary to treat the symptoms of the disease according to the individual.