Do everything you can to make sure they stay hydrated. My son had it at 24 months and he couldn't even keep water down. We had to make 3 trips to the ER before they would take us seriously. The third time, I walked in with him limp in my arms and his eyes rolling back in his head from dehydration. Even then, they kept him for one night and as soon as we got home he was throwing up again. He threw up for 9 days straight. I could be wrong, but I don't think adults usually get it. The doctor said if we got it from him we would only be sick for a day or so. Good luck, and trust your instincts if something seems wrong, especially with the little guy! I have a 2 1/2 year old son and an 8 month old son if you are ever interested in getting together for playdates or anything.