Conversation: The conversation between human and AI assistant.
[|Human|] My 11 year old son observed blood in dribbles after urinating. The blood was observed on tissue paper while wiping. One time was bright red drop, then next time bright red stringy, fiber like, then another time dark, rust colored blood droplet, liquid, on the tissue. The urine test in the Dr office detected high white blood cell count but the culture found no blood in urine nor bacteria. What could be the cause of this and should there be further testing?
[|AI|]  The culture might have been an erroneous one, but the more likely thing is that the blood is due to sterile inflammation of the urinary bladder or the presence of gravel or small stones in the bladder. You should repeat the urine test, as well as take him for a radiograph and a kidney-ureter-bladder (PUB) ultrasound to rule out non-infective causes of bleeding such as a stone or presence of gravel.