How to get my corn snake to eat?

i have a silver corn snake that is about 47cm and for about 4 weeks now she has not been eating i tried all the tricks to get her eating.if she takes the rodent she will just regurgitate the food for some reason.i had her on fuzzes befor and i thought it was to big so i gave her pinkies and she ate it and 2 days later she regurgitated it.what can i do please help