How to stop vomitting? How long does gastroenteritis (stomach flu) last and how to keep energized and hydrated?

Depends. If its moderate nausea then oral agents like Compazine (prochlorperazine) can be used. If even pills can't stay down rectal compazine (prochlorperazine). Once this calms the nausea use this as an oppurtunity to take in ice chips. Dont over do it . If you push too hard you will only throw up again and will progressively get more dehydrated.