what could it be?

Usually if they aren't running fever I don't worry and definitely don't rush to the er when they do. If I can get it controlled I just let it run it's course. My 1 yr old had a tiny cold for about 2 days, then Friday vomiting and diarrhea, yesterday he was grouchy and now he just awoke 5am with fever (don't know can't find themometer) just wondering what you thought it could be?

Just gave him pedialyte and Motrin, now he's sound asleep.

Sounds like a bug of some sort. Just let him sleep and keep up the hydration and Tylenol and if it seems to get worse, go in.