One of the great conspiracies of the Millenium - the myth that Flexible Cystoscopy is NOT painful! ;-)
Urology must be the ONLY medical specialism where EVERYTHING they do is painful, almost all other medical procedures have local anaesthesia to fall back on, or General anaesthesia is automatically used for larger scale interventions, but other than about 2 inches at the penis end, there is no means of anaesthetising the rest of the urinary tract, so naturally it isn't going to be a laugh! Uriology departments are SO busy, that has never been seen as an option other than for children, so I suppose they just get used to causing pain, like in pre-anaesthetic days, so they just play it down.
I Can assure anyone reading this, IT IS painful, usually more so for men than women, as the prostate is a big part of the pain, but I doubt it is exactly comfortable for women either.
How unpleasant that pain will be is not simple to quantify, because it is going to be different for everyone.
Male bravado is a strange thing, AFTER the event - At the time, they scream just as loud as those who don't have so much of it.(Others were doing plenty of it as I waited to be seen! Like everything else, it is a mix of luck and circumstance how it goes:
If you are lucky, have the right physical anatomy (size means EVERYTHING), have it carried out skillfully and with the careful application of anaesthesia (although it has very little real effect, and debatably may actually make the after-effects worse, and peeing more difficult!), then you will have a far less unpleasant time than those where things don't work out in your favour.
Prostate Enlargement WILL make it worse, as you might expect, it slows down urine flow going through, so it will certainly get in the way of a scarily thick tube. More likely to bleed as it can tear the tissue to a varying degree, that hurts, take my word for it. I only have slight BPH, but it still bled profusely.
Something few mention - Pressure during the procedure can be distressing for some, not for others, no idea why, maybe related to technique by those carrying it out, or just personal anatomy? I found it nearly as bad as the prostate pain, and lasted a lot longeer than that.
Afterwards, infections... luck of the draw, Antibiotics can be given, and these MAY be Fluoroquinoline type, which have SERIOUS risk of horrendous tendon damage and other side effects, avoid unless life-threatening as other types have far less serious risk of these side effects. Talk the options through beforehand. For once, I was lucky, didn't have one, although I have had urinary tract infections before.... not nice.
Don't count on getting back to work (same day some info sheets say!) I found it was some days before I was able to leave home for more than a few minutes at a time - peeing dozens of times daily, I was not confident that I would pee at all for a couple of days, during that time a LOT of burning, eventually and slowly, (very slowly it seemed) getting better, sleep deprivation during that time becomes very wearing, and because peeing is painful, you are wide awake every time too. It was a couple of weeks before I was starting to get more relaxed about urination, something few seem to mention - it was a LOT longer before I was confortable about ejaculating, I was far too terrified to try for about 6 weeks, then the next 5 or 6 times had fear of ejaculation as it HURT. Bit of a pssion killer.
Eventually I stoped thinking about it ALL day, (that was over 2 years back) until now I need to have this again - I haven't slept for a week, but at least this time I have cancelled everything for 2 weeks so don't have that worry of having to cancel comittments at short notice like last time.