Physiological diarrhea is a natural physiological process caused by lactose intolerance in children due to the presence of substances in breast milk that inhibit the activity of lactase, thus causing diarrhea. This type of children, if they can eat, drink and grow meat, do not need medication, but if the diarrhea is aggravated by cold or too much food, or even hunger, they can be treated with gastrointestinal mucosal protectors or medications that regulate the intestinal flora. For children with obvious diarrhea and a large number of diarrhea can be switched to lactose-free formula. However, if the diarrhea is mild, it is recommended to continue breastfeeding, and zinc and trace elements can be supplemented appropriately.