Mine was accomplished using GoLytely, which is a polyethylene glycol solution.
One is provided with a gallon of the stuff and expected to consume it over a several hour period. I tried to get the unpleasantness over too quickly and vomited back the last quart. I don't look forward to doing this again.
It's got pineapple flavoring in it.
Yep - that’s sort of old-school but very effective. A friend of mine claims his was relabeled “GoSwiftly”. My citrate treatment was three 10-oz bottles taken over the course of an afternoon and evening. Lots less unsettling but very effective. Oh, my, yes, very very effective... ;-)
“polyethylene glycol”
Is that anti-freeze!? :-)