Hi, Just Wanted To Ask...i Have Been Having Dysuria For

hi, just wanted to ask...i have been having dysuria for almost a week now...seen an urologist already, did a scope in the bladder and there were no findings just bladder irritation....I'm having radiation(pelvic) now and its my 3rd week already....urologist said could be from the radiation that's causing my bladder irritation. Had my urine tested and were clear...no infection....prescribed with pyridium to help with the pain...its my third day today taking it and it seems like its not working...I still experiencing pain and burning when I pee....I have read on pyridium that I shouldn't be taking it more than 2days, but it still hurts....my question is should I still be continuing taking the medication or wait patiently because of the radiation's effects.....Can the scope pick up any stones in the urethra....I kinda remember a ct scan done last year that I have a approximately 3mm sz stone in my left kidney....can that be another explanation to my dysuria despite taking pyridium....Please I need your respond so that I can ask my doctor again when I see her next week....Thank you