I was in same scenario and my former GI doc would not add prednisone even though I knew I was flaring in addition to the cdiff. It was only after I called him on his cell phone telling him about my symptoms while on the toilet that he offered to get me on the schedule the next day for a flex sig. Sure enough, flaring in addition to cdiff. My remicade infusion was moved up, pred was added but I ended up in the hospital because of the nausea. If you can't keep your meds down, you need to call. Unfortunately for us, we have to sometimes be our own advocate for the proper care.
It's true that prednisone shouldn't be added unless you're flaring but it definitely can be done. If you're actively flaring while on remicade, I agree with previous poster to get remicade levels drawn. You won't recover from your flare unless treated. Remicade infusion could be moved up, dose changed, prednisone added, etc. I hope you feel better soon and totally empathize with your state of misery.
43 yo; dx 2001 left sided UC
asacol max dose for several years
prednisone and rowasa when flaring
remicade since 2009; zofran, canasa
Factor V Leiden-blood clots x3
gabapentin, cymbalta for neuropathy in feet most likely from humira. Insurance denied lyrica so now on low dose methadone