Cystoscopy
Blood in urine can be a number of reasons from nothing (I know of people get blood clots for example with some remaining specs of blood from over exercise !) to something else ie: damage from passing a stone.
The fear of the Cystoscopy if far worse than the procedure itself - I have had about 4.
The Cystoscopy itself allows the Urologist to check all the way from "exit" - to bladder via the Urethra (via a camera which I was able to watch on a big screen) for any obvious problems, blockages or other.
Its relatively painless, but uncomfortable (and mentally challenging to get over what they are doing) - but they use a local anisthetic gel that deadens any pain.
You will probably experince a mild stinging and discomfort afer the procedure for about 5 mins then it goes.
They will tell you if they find anything there and then...or may require further tests ie: CT Scan / Ultrasound etc to check for other issues (ie: more stones)
Dont try and second guess the issue - you will worry yourself completely unnecessarily - the doctors will sort it.