I had a cystoscopy due to blood in the urine. Honestly you could do a stand up routine about it.
Firstly they take you into a room with a couch. Then they say "We're going to leave the room now. Take off your trousers and underpants then get on the couch and cover yourself with the sheet."
Why? The first thing they do when re-entering the room is to whip off the sheet. I mean they're going to see everything anyway, why bother leaving?
Then they injected the old man with a lubricant/anaesthetic which stung like crazy for a minute. Then they get out the camera. How they get it up the old one eyed trouser snake I don't know but it fitted. Everything clenches and I thought I'd shat myself but I'd just clenched up a bit of the covering on the couch.
The weird thing was afterwards. They'd run a saline solution into my bladder so they told me to try and have a pee. Everything was numb so you could see yourself going but couldn't feel anything.
A few years ago, for a period of about one year I had to use a self administered single use catheter three times a day. You get quite used to it after about the thousanth time!