How long is someone who had a VERY mild stomach bug contagious for?!?

I was supposed to visit my boyfriend for the 4th of july but on sunday he got home from work and was nauseous and dizzy and felt like he had the chills and muscles ached a little. He did not throw up once --but felt like it- and he just had -just once- very mild diarrhea the next morning on monday. so it was very mild but If i'm going to be intimate, kissing and such, how long should I wait to be sure I won't catch it?! Please answer thank you!!