x abagillion on what steppingup said. When I've come off opiates in the past, before trying the sub route...and most notably coming off Effexor, which also can help w/pain and depression-related pain but has nasty w/d syndrome...I actually thought I had a uti which I wasn't aware of that had developed into a kidney infection. My back hurt THAT much - it was excruciating - but the pain did subside over time.
I assumed it was a chronic problem you were talking about, and it may very well be, but just wanted to add that.