What is the difference between spitting up and vomiting?

"Spitting up" or regurgitation is a normal occurrence in the first few months of life. As the stomach expands and the muscle that controls the opening into the stomach strengthens, your baby will spit up less. Spitting up is generally less than one-fourth of what the baby just ingested and drips down the front of the baby or you. Vomiting on the other hand is when the baby spits up more than half of the amount they just ate for several feedings in a row. Vomiting is also associated with more force so the vomitus is a distance from the baby and is referred to as projectile vomiting.

Donna Dixon, HES Extension, College of Human Environmental Sciences, University of Missouri-Columbia