Bausch Health, the maker of Xifaxan has a patient assistance program. I have not tried it yet but my doctor sent me the paperwork. you can download the forms from Bausch. Good luck to you......
Go to http://www.bauschhealthpap.com/

I too have been denied, after many years of being covered with a huge co -pay.
The sad part is that it is available in other countries for pennies on the dollar, compared to what they want us to pay.