Seriously, I don't know, but around here, a stomach virus has been going around. Reportedly, it hurt a grown man so much he laid down and rolled on the floor moaning. SERIOUSLY. I'm lucky not to have it now.
I have the same symptoms really. Except for the throwing up. I've been feeling nauseous though. It's the flu. The flu this year is horrible and it's supposed to be the strongest one ever. Drink plenty of fluids, and cover your mouth when you sneeze or cough. Eat healthy too. That way your immune system can fight off the virus easily.