Kidney surgery meds for us ????

I had a kidney stone like a ****leburr pass about 6 months ago, and like a dummy, did NOT go get things checked out. Now I have scar tissue blocking 75% of one ureter/kidney. I DO have kidney damage now from it, but percentage wise; we can't tell until the blockage STAYS gone ! It was cleared out once, and didn't stay; so now I am scheduled for an OPEN surgery to remove that part of the ureter. PROBLEM: What CAN we take for the bladder spasms caused by that *^&)& kidney stent they put in for 6 weeks after surgery ???? I can NOT endure that pain again ! I was given Detrol LA, ( A time-release med) even AFTER I told the doctor that we can't "do" a timed release med. Plus, it didn't work ! My PCP gave me Ditropan tablets that I took am & pm...that was do-able, but I wonder; is there something better ?