Should I take my son to the ER? Fever, vomiting, stomach pain...?

I agree, he needs to go. He could get dehydrated, not just from the vomiting but from not drinking anything and having runny bowell movements. He's been on and off w/ the fever as well as the lethargy. Remember, you ALWAYS go on the side of precaution, and this is exactly why we have insurance. Use it and get that boy better, and you will feel better knowing you did the right thing. Even if the doctors were to say "oh he just needs xx medication and its over the counter" won't you feel better hearlng that from a doctor?