You can generally appeal to the insurer. Forcing you (financially) to discontinue a successful treatment isn’t such a good idea, and they might not dig in their heels. The Xifaxan is costing them a lot more than Tindazole. Appealing can work if your doctor is willing to go to bat for you. 

Are you taking the Flagyl with Cipro (as you did the Tindazole)? Flagyl alone never worked for me, but it works well for me with Cipro.

I am taking Flagyl with Cipro. I am also on Pred and have cut it down to 12.5 mg a day from 40 mg.

My doc has been trying to wean me off of pred and antibiotics. I am on humira 6 months now, but it does not seem to be working.

I have not asked them to approve Xifazan yet as I still have some from previous insurance coverage from December.

Thank you for your reply.