Spitting up like a fountain in a 3-month-old baby is usually not normal and may be caused by improper feeding, gastrointestinal infections, central nervous system infections and so on. 1. Improper feeding (e.g., inhaling too much air during feeding) can cause babies to spit up. In this case, you can minimize spitting up by patting your baby’s back, encouraging your baby to burp out the air, and holding your baby upright for a while instead of letting him/her lie down immediately after feeding. 2. Gastrointestinal infections, central nervous system infections and other diseases can also cause babies to spit up, babies in addition to frequent spitting up, will be accompanied by other symptoms, for example, gastrointestinal infections in children will also be accompanied by abdominal pain, diarrhea, loss of appetite, and other symptoms; central nervous system infections will also be accompanied by headache, fever and other symptoms. If your 3-month-old baby is spitting up like a fountain, there may be other causes, so it is recommended that you go to the hospital in a timely manner, complete the examination to determine the cause of the illness, and then give targeted treatment or therapy under the guidance of the doctor.