I have had diarrhea for three days, and have vomited twice. I went to the doctor today and she told me it was bacterial food poisoning. She prescribed me sulfameth/tmp as well as ondansetron for the vomitting. However, my main problem is the diarrhea, and it is getting worse. I have leftover buscopan from a doctors visit after having diarrhea in Spain. .. Can I take the buscopan and mix it with my antibiotic? I m so dehydrated , and getting essentially diaper rash from going so often. I need it to stop.