Hi..my Daughter Has Been Vomiting Very Much And Lose Motions

hi..my daughter has been vomiting very much and lose motions as well...doctor said it can be gastritis...no pain i stomach but yes fevhere. Doctor gave Emset and Zifi 300 as medicines. its been two doses but no improvement rather she is becoming very week. She is just 3 yr old and weights 11.5kg now. pls suggest something for quick relief as she is not eating anything