I agree w/Margot....You need to get your puppy to a Vet!
You don't say how old he is or if he has had any of his Vaccines....What your describing could be anything from an upset tummy to something Fatal like Parvo....We have no way of knowing what's wrong.....Dehydration alone, from all the Vomiting, can be extremely serious in a puppy....
Please, get him some help ASAP.....I hope he gets better...Let us know what happens....Karla
Oh my, I'm so sorry to hear this. There is absolutely no way we would be able to tell you wht is wrong. It can be any number of things. I think you had better get a call in to your Vet. It could be a virus, Parvo, obstruction, poison, etc.