Spitting up in a full-term baby may be caused by a small stomach capacity or improper breastfeeding, or it may be caused by a disease. If you find that a full-term baby is spitting up, you should go to the hospital promptly for examination and diagnosis, and if necessary, treatment. 1. Small stomach capacity: The stomach capacity of a full-term baby is relatively small, and the muscle tone of the esophagus is weak, the cardia is flaccid, and the neural regulation of the gastrointestinal tract peristalsis is poor. These factors lead to easy reflux of food in the infant’s body, thus causing the phenomenon of spitting up. This is a normal physiological phenomenon, and when the infant reaches six months, the spitting up phenomenon will slowly decrease until it disappears; 2. Improper feeding: the amount of milk fed at one time is too large, the feeding tools are not suitable, the way of feeding is not correct, and the infant’s vigorous activities after eating can also cause full-term infants to spit up. These conditions can irritate the infant’s gastrointestinal tract and cause regurgitation of milk, resulting in spitting up of milk. It is recommended that parents choose the right feeding tool for their infants, learn how to feed them carefully and feed them in small amounts several times, and soothe them in time after feeding to prevent vomiting; 3. Diseases: congenital pyloric hypertrophy or stenosis, intestinal obstruction, intussusception, gastrointestinal inflammation, encephalitis, craniocerebral trauma, craniocerebral tumors, and other diseases may cause infants to vomit. If the infant does spit up because of illness, most cases have other symptoms at the same time. You need to pay close attention to the baby’s crying and mental state and go to the hospital for diagnosis and treatment in time, so as not to delay the treatment period.