There are many reasons why babies vomit, mainly including: physiological factors, digestive system discomfort, etc.. 1. Physiological factors: for newborn babies and young children, due to the gastrointestinal tract is not well developed, the position of the stomach is a horizontal state, so when the milk is too fast or swallow a lot of gas, may cause the child to spit up, vomiting performance. 2. digestive system discomfort: for example, the baby eat too much food caused by the gastrointestinal tract, resulting in indigestion, which in turn produces vomiting; the baby ate spoiled food, resulting in acute gastroenteritis, resulting in intestinal spasms and vomiting; gastric ulcer, pancreatitis and other digestive disorders can also cause gastrointestinal dysfunction and lead to vomiting. In conclusion, baby vomiting, there are physiological reasons and pathological reasons, if there are other symptoms, we recommend timely medical treatment.