Children and Vomiting
If your child has persistent vomiting and is not keeping anything down, check him for signs of dehydration (less frequent urination, dry mouth, no tears, and sunken eyes). If he is not dehydrated, then you can give him a break from drinking for an hour or so and then slowly begin to give him fluids again as described below. The most common error is giving a thirsty child too much to drink too soon, which causes them to continue vomiting.
We recommend giving very small amounts (1-3 teaspoons or medicine droppers) of an oral rehydration solution every five or ten minutes. Even though their stomach is very upset, most children with persistent vomiting are able to keep this down and over an hour or two they end up drinking quite a bit of fluid that can keep them from getting dehydrated.
Once your child is keeping a few teaspoons of fluid down at a time without vomiting for a few hours, you can then increase him to 2-3 tablespoons every five to ten minutes and after keeping this down for a few hours he can then drink an ounce or two at a time.
You should continue to give the oral rehydration solutions in small amounts until the vomiting improves and then restart his usual diet with extra fluid every time that he has diarrhea or vomiting.