Hi Doctor, My Daughter Is 3.6 Years Old. We Travelled

Hi doctor, my daughter is 3.6 years old. We travelled to India last week for a 5 days religious trip to haridwar. She started having diarrhoea and vomiting. The doctor gave her an injection also, we are back to our native. diarrhoea has somehow stopped but she is vomiting 2 times a day - morning and evening, we are giving her ondem syrup but the vomit does not stop completely. What do we do?