Newborns have vomiting for the following reasons: 1. Distinguish whether it is overflowing milk or real vomiting. The main reason for this is that the newborn’s stomach is horizontal and the pressure of the pylorus is relatively high, which is a normal phenomenon for newborns and will not affect their growth and development. 2. The newborn has a gastrointestinal tract malformation, such as intestinal malrotation or intestinal obstruction, which leads to neonatal vomiting, and also such as pancreatic atelectasis, which is a relaxation of the cardia. Neonatal vomiting. In short, if a newborn is determined to have vomiting, he or she must go to the hospital and actively look for the cause of the vomiting and treat it accordingly.