Do I take the baby and run, or stay and risk it?

My boyfriend came home today from a trip out of state and on the way home he experienced vomiting and diarrhea. He says he feels absolutely fine now, but I’m not sure if it will return suddenly. My mother got word of this and she’s worried my son might catch it just in time for Thanksgiving. She wants me to come stay at her house for a few days. My family are germ freaks and would prefer living in a plastic bubble. I am not so insane, but of course I would like to avoid my son catching the flu if possible.

How can we even be sure this is the flu? No fever, no body aches. Just a bout of stomach issues that might be over now. Is the flu airborne? Should we stay and just sanitize everything? Or should we play it safe and stay with my mother?