My Son Woke Up Throwing Up And Has Been All

my son woke up throwing up and has been all day it turned into orange fluid the last few times. he wont drink anything cause he feels nausues after. even water. a few sips here and there maybe. he passed out once this morning and has never done that. I pass out a lot when I'm sick so I didn't feel too concerned yet. but now he is complaining about his back hurting as well. could there be more wrong? he is 17 btw.