I have had a few bouts of kidney stones....
It us easy to stray into melodramatic exaggeration, but I can quite confidently state they have been the most excruciatingly painful episodes I've ever experienced.
Mine start with chronic backache, progress to hurting so much I'm literally scrunched up - peeing blood as I go - and then the inexorable passage of the stones into the outside world. It is always something of an anticlimax when it feels like you are trying to pass something akin to a red hot pineapple wrapped in barbed wire strapped to a backwards umbrella... and out pops summat the size of a small pea......
On the upside, the relief once a stone DOES emerge is quite literally instant.
Without wanting to sound all gung-ho, I think k I've a reasonable pain threshold, but ***k me, kidney stones fair make me sag at the knees.....
They really are unpleasant.