We just went through this. Our pediatrician said 1 teaspoon of pedialyte and then wait 5 minutes. If he kept it down then give him another teaspoon, etc. After an hour of keeping the pedialyte down, up it to a tablespoon every 5 minutes. Make sure all liquids are room temperature, and don't give them anything to eat or drink for 30 minutes after they have thrown up to give their stomach a chance to settle down.
at 6:42 PM on May. 3, 2011