Bladder stones after Prostatectomy

I had my prostate removed in January, evidently there was a suture remaining in my urethra where my bladder was reattached. A bladder stone formed on this suture. By March I was in a lot of pain. I went back to the Dr for a cystoscopy which confirmed the stone. I was scheduled for surgery two days later and the stone was removed. Actually, he found and removed a few stones (5cm to 9cm each). Now two months later I've started passing more bladder stones (1.5cm-2cm) and having the same symptoms.
Has anybody ever had this problem? I've never had any problem with any kind of stones prior to this.
I guess the good news is that I'm cancer free. However, I do not look forward to a cystoscopy every couple of months. That's almost as bad as the biopsies.
BTW: I peed bright red blood today after mowing the lawn.

I was diagnosed with the problem today and I'm so happy! After I presented a gross hematuria 10 days ado, I was convinced that my bladder had been invaded by a tumour. I am so relieved. I look forward to the surgery to remove it after 5 years of problems.