The norm is that 'sedation' (if offered) is done via the endoscopist - so at best is midazolam/fentanyl - the exact values are set by the facility themselves (seem to need a FOI request to obtain these up front - noone has answered yet) - so there is some variety there. So it's understandable that some report it as fantastic where as others report it as being totally bollocks. I found that the actual internal cost to the NHS was about £394 - so fuck all and hence happy to waste it with multiple attempts.
Some folks are ultra tough and do it without - no idea how but is that the norm? Maybe it is.
Propofol is the next level up - but needs to be pre-arranged etc. as it needs an an anaesthetist - hence the extra cost/waiting list - or as I have experienced, bullshit to say that the first approach is just as good and everyone has mis-remembered.
Anyway, we are all different and I think this should be accommodated - risky if there are delays like Words says above "Which isn't great when they need to do biopsies for potential cancer."
So I think the vast majority of people are happy to try, most succeed, those that fail re-attempt, don't worry about it and all is well - but for the folks that are troubled from the start it's an uphill battle to be heard - like Words I too have a delay that's seen "as my fault" - over a year now but that's my choice.
Not related, but I happened to watch the 1960's Twilight Zone where William Shatner keeps seeing a gremlin on the wing of the plane - IIRC the flight attendant offers a chill pill as if it was normal solution to calm everyone down - we have these at our disposal and they cost sod all now - so why can't we do the same?