Stomach bug or food poisoning, how contagious?

My whole family went on vacation last week and all of us got sick, the only one who is still healthy is my 6mo son who is breastfed. We all caught it in different increments of time, within three days of exposure. But we all ate the same food on the trip. Could this be a bug or food poisoning? I've recovered but my husband has not and he got it before I did. Can I catch the virus again?!