Usually, after 6 months of age, newborn babies will slowly disappear from the vomiting phenomenon. The reason why babies before 6 months of age will spit up is that the stomach of small babies is horizontal, the function of the cardia sphincter is weak, and the capacity of the stomach is very small. It usually takes about 6 months for the digestive system to gradually improve, the function of the cardia sphincter is enhanced, and the capacity of the stomach increases. At the same time, after 3 months of age, the baby’s head can be erected and the body position changed from mainly lying down to upright, at which time the gastrointestinal function has significantly improved and the vomiting will be reduced. When your baby is spitting up, you should try to keep him/her in the lateral position to prevent choking or lung infection caused by milk inhalation. In addition, new mothers and fathers should pay attention to avoid overfeeding their babies, and burping after feeding can effectively avoid and reduce spitting up.