Why Am I Having Pain In My Right Lower Flank?

hi im 36 year old male i had kidney stones in march last year after lithotripsy my pain went for around 4 weeks since then my pain in the right lower flank has never gone. Its so bad that i'm on zormorph for the pain 2 operations later and 4 ct csans still no diagnosis. chrones and appendix ruled out . bowel ok .. please help im at my whit's end with the pain and also the drugs im on. my local hospital have said there is nothing else they can do. So my GP refereed me to another hospital for a second opinion ..... any ideas ???? best regards Mark