It is good that the scan has come out clear for any kidney stones. Causes can be divided according to the affected organ and they are Kidney conditions (infection, pyelonephritis, kidney stones, polycystic kidney disease), Bladder conditions (cystitis, bladder polyp, bladder tumor), Urethral conditions (Sexually transmitted diseases, urethral injury, vaginal inflammation), and certain bleeding disorders. It can be due to chronic UTI or vaginitis also.
I would suggest that you consult your Doctor so further investigation can be done. You Doctor may request for some blood tests, urinalysis, urine culture, and an ultrasound or CT scan.
Hope it helps. Take care and do keep us posted on how you are doing.
I have a feeling of irratation in my bladder and an urgency to pee every 30 minutes or so. I went to the clinic and a urine sample was tested. They said there was no bacteria in my urine but there was a trace amount of blood in my urine (I did not visually detect blood in my urine). I was prescribed a 5 day dose Supra twice daily and to drink 12 glasses of water a day. I am on day 5 and I still have a feeling of urgency to pee. I have an uncomfortable feeling in my bladder/urethra but no pain when I urinate just the urgency. My pee does not come out in a strong stream but a moderate stream. No pain in my kidneys. Any thoughts on what this might be?