Overfeeding will cause increased spitting. If a child has reflux, overfilling the stomach by excess feeding raises the likelihood of increased reflux. Even the usual amount of reflux and spitting seen in healthy infants will increase with overfeeding. Reflux can be evaluated by doing an upper GI series or placing a pH probe in the esophagus. If your baby is happy, healthy, and gaining well, there is no need to pursue diagnostic testing.
Most infants stop spitting up when they spend more time upright.
As they grow and spend more time upright, the rotation of the stomach changes making the gastroesophageal valve more competent, thereby decreasing the reflux. Toddlers don't walk around spitting up. Most babies spit up, but they can usually manage to turn their head in such a way as to keep their airways open. Occasionally babies spit up forcefully so that it comes out through the mouth and nose. This may result in some choking, but it will not obstruct the airway.