My daughter had a stomach bug that had her vomiting every ten minutes or so and it is very scary.
I would not give any liquids until he can go 1 hour without vomiting. After that do one tablespoon of gatorade every ten minutes. If he falls asleep don't wake him, just resume once he wakes up. If the vomiting goes on for more than 12 hours or he seems very dehydrated call your pediatrician and have them give you a prescription for zofran or take him to ER for fluids and zofran (anti nausea med). We had to do this once with my daughter because the vomiting makes them dehydrated which causes vomiting and you need help in stopping that cycle. This advice was given to me by our Dr when we were going through a viral episode with my daughter.
When dealing with crohn's the thing I look for with my son is pain with vomiting, because that can signal an obstruction. Or if he is vomiting fecal matter. These are emergency situations and he should be taken to an ER.
If you aren't seeing either of those situations, I would hang tight. But trust your mommy instinct and go to the ER if you think you should. The worst that can happen is they send you home after being in the ER and they have given him something to treat the nausea and dehydration.
(((((Hugs))))))) I know how hard this is, hopefully he will be feeling better by morning!
