My daughter is about to turn 5, she was prescribed SMZ-TMP a few ...

My daughter is about to turn 5, she was prescribed SMZ-TMP a few days ago in order to prevent another ear infection. She has been having terrible diarrhea, which is obviously normal, but along with that she started vomiting, she is now vomiting every time after taking the medication. She has a loss of appetite and has barely ate anything in the past 3 days! The poor thing has been battling diarrhea while throwing up at the same time along with terrible stomach pain/cramps. I am calling the doctor first thing tomorrow morning to discuss discontinuation of medication etc.