My son came home from school 2 months ago with diarrhea, stomach pains, and his burps smelled really bad. His diarrhea lasted 3 days. One month later he came home with stomach pains, threw up 1 time, his burps smelled really bad, and had diarrhea for 2 days. I started him on a probiotic and he took it for 3 weeks. He stopped taking the probiotic 3 days ago and started today with his stomach hurting and bad smelling burps again. What do you think is going on.