Diarrhea in newborns who are breastfed is medically known as “breast milk diarrhea”. Mostly seen in newborns who are exclusively breastfed or breastfed mainly. The reasons for diarrhea in newborns eating breast milk may be the following: 1, the prostaglandin content in breast milk is high, the substance promotes the smooth muscle movement of the small intestine, increasing the secretion of water and electrolytes and producing thin stools, the infant body will gradually adapt to the prostaglandin in breast milk. 2, treasure to lactose intolerance, the body lacks lactase. Such a baby can be consumed in small amounts several times to reduce the lactose intolerance reaction, but also can be changed to feed low lactose milk or rice soup, can make the baby lactose intolerance situation is greatly alleviated. As the infant grows, lactase will also gradually mature and increase its enzyme activity, thus breaking down, digesting and absorbing lactose. 3, pay attention to the mother’s diet, if the mother often eat a lot of oil, high fat, stimulating food, resulting in the milk contains more than the baby’s needs, it will make the baby diarrhea. In addition, the mother should avoid eating foods that can cause allergies in the baby. For example, if the baby is allergic to milk, eggs, seafood, wheat, etc., then the mother will also experience increased diarrhea and even blood in the stool if she eats these foods, and some babies will have significant eczema. If the mother’s diet adjustment is still not enough to improve the baby’s diarrhea, she can give her baby some lactase to help digest the lactose in breast milk. In conclusion, mild cases of physiological diarrhea in newborns do not require treatment and can continue to be nursed, so that the lactase enzyme will gradually develop and mature, and the enzyme activity will increase, gradually being able to break down, digest and absorb lactose, and the diarrhea will gradually improve. If severe diarrhea causes growth retardation, malnutrition, etc., prompt medical treatment is required.