Cystitis cystica develops from an enfolding of normal bladder lining cells (urothelium). The center then liquefies producing visually distinct small cysts. These are benign and have been found in 60% of normal bladders at autopsy. These changes are associated with inflammation may or may not be associated with symptoms and, in many cases, probably represent normal findings.
In any case, I would suggest being re-tested for infection - with a urine test looking for bacteria or STDs. If there is concern about continued discomfort, I would suggest a cystoscopy, which can evaluate for any tumors or cancer of the urinary tract as well as anatomical disorders that can cause discomfort.
If that route is not revealing, you may want to consider tests for prostatitis, including prostatic massage and testing prostatic secretions for infection.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Thanks,
Kevin, M.D.