I am 33 years old male and unmarried.About 10 years ago I had severe pain in my left ureter.Upon ultrasound a tiny stone was seen in left ureter.After some days that stone was passed out and everything was fine.This thing happened with me every year,pain in ureter,ultrasound,small stone,passed out and everything fine.This continued to happen for several years.About 5 months ago same thing happened and several tiny stones were seen in left kidney,ureter and bladder.The urologist gave me antibiotics and I drank a lot of water but pain in bladder was not over.I had another ultrasound but this time there was no stone in ureter,kidney or bladder but for the last about 3 months I have been feeling pain,burning and warmth in my urinary bladder and urethra especially this increases when i urinate.I have seen 3 different urologists and had ultrasound 4 times and one I.V.P during the last three months but the problem persists.During this I have also used three antibiotics ciprofloxacin,cefixime and saproxin but the problem is not over.Last time the Urine D/R showed Puss cell 20 to 25 and Red blood cells 4--5.Plz advise me what should I do? The urologists say there is no need of cystoscopy.Plz reply as soon as possible