4 year old toddler with stomach flu?

My baby sister is 4 years old. She began to vomit early this morning and continued throughout the day until now. I'm worried because everytime she eats something, even if it is water, she would soon vomit. She also has a small amount of diarrhea. I recently went to the clinic and the doctor suggested she may have caught the stomach flu.. But now she continues to vomit and I'm worried with her having nothing in her stomach for a whole day. I want to give her some Gravol, which indicates that children 6-12 years old should take 1/2-1 tablet. So I was wondering if I broke the tablet into 1/4 will it still have any affect? Is it best not to give her Gravol Adult tablets? Otherwise, does anyone have any suggestions as to what to do to ease the vomitting? Thanks!

Ring the emergency doc NOW (number will be on the doctors answerphone or in the yellow pages, or try NHS direct http://www.nhsdirect.nhs.uk/contact/ on 0845 4647 24 hour service)

if she's not keeping liquid down she could get dehydrated fast.

Don't give her anything for an adult unless a doctor advises!

Just make sure she drinks something, even if you have to give it to her with a syringe.

Honestly, if she can't hold anything down for an extended period, you need to take her to dr and get her a Phenergan suppository. Sounds like Rota virus to me. My daughter had it when she was two and ended up in the hospital. Don't wait, get her to a dr first thing in the morning.