I have had one of these annually for the past five years. Back then, it discovered a growth in my bladder, which was (a few weeks later) removed. However as there was possibility of it growing back, I am summond to the hospital for this procedure to check on it.
When |I went this year - and no regrowth - I was told next year will be the last year they do this test as if it does no grown back in five years, there is little chance it will do so.
It is slightly uncomfortable, not the nicest of tests - but no real pain. Staff have always been loved and one nurse usually holds my hand through and I am able see the screen as to where the camera goes.
Best if someone can take you home afterwards, I get a taxi back. Then do need to take it easy for the next day or so. Do remember to take in lots of fluid (water preferred) over the next few days.