Once I had my last attack (at 3am and debilitating - about attack no 8 and, by far, the worse), I went to the GP next day - onto the Omeprazale (excuse my spelling) and I was ok from there through to the op some 3 months later....however my bag was only about 1/3rd full of crystals around <5mm.
A salutory message is that one of my co-in mates was pretty full and he was 1st down and they found he had burst, thereby needing a 4 hour op to clean up the mess and prevent the side-effects, thereby delaying the other two (inc me as number two in line) by five hours.
I knew him - he is my sis's butcher and he was pretty full down there - but to have the authorities even risked a burst, that I find hard to fathom, and so did he.......he ended up with the slash and burn on his torso..... Maybe that is a downside of being with Cornwall NHS - to be fair the nursing was good, though I had to spend a night in, being a little slow to come around and my O2 levels. Once over that I was not assisted by having some diarrhoea victim moved into our "four" at 3am.......