I am on pantoprozole for acid reflux and once a week I get rotten egg smelling belches followed by diarrhea. Could it be caused by medication or what?

Probiotics. These medicines have been reported to alter healthy flora in the colon and make one succeptible to overgrowth of c difficile infection. This could be the diarrhea. Probiotics and a diet in short chained fructoligosacchardies from bananas, garlic, asparagus and tomatoes and whole grain wheat products can help establish normal flora while on these medications.