Suggest Treatment For Fever , Diarrhea And Vomiting

HI my 27 y/o daughter has been having frequent sudden onset vomiting and diarrhea about every other weekend x 2 months. She has been to the doctor who has given her Pantoprazole sodium 20 mg which she takes once daily which seemed to help until this weekend. She woke at 7:30 a.m. with the same symptoms plus weakness, a slight fever (again).