What Causes Diarrhea, Abdominal Cramps, Chills And Nausea?

I had diarrhea yesterday as well as cramps, chills, nausea,and weakness. This happened after I ate some barbeque that we had eaten some before and frozen the next day. I heated it in the microwave. I do not know if I had a virus or food poisoning. I do believe it was food poisoning. Today the pain is gone even though though I had a 99.3 temp. The diarrhea is just about gone too. Thank you. YYYY@YYYY