I’ve only dehydrated when I had the temporary loop ileostomy; in fact I dehydrated twice per month, every month over 6 months; each occasion resulted in emergency admission into Hospital by ambulance for IV fluids
I also suffered from renal failure, which luckily, was treated in time before lasting kidney damage occurred.
My potassium level was also dangerously low.
I dehydrated to such an extent, as apparently, due to the loop ileostomy, there wasn’t enough small intestine to absorb my fluid intake, despite how much I was drinking.
Since takedown, I’ve had no serious episodes of dehydration, although I do suffer from fatigue, which I believe is either a salt or magnesium deficiency, maybe both rather than actually dehydrating