Kaplods - that is heartbreaking and hilarious at the same time :)

My big cat hangs his butt outside the box too. I've found 2 things that work great. You can get a sterilite tote with high sides, so that it's impossible to hang his butt out, or what I use now, is the Booda Clean Step litter box (I don't have enough posts to put in a link, but you can google it).
You can get them in really big sizes, and they have a ramp to the side so it's impossible to poop on the floor (although they could poop on the ramp, but my cat never does for some reason).

The small sweater box is working very nicely. It's sides are a little higher than a typical non-covered litter box, and it's dimensions are about 3 inches wider and about 6 inches longer than her old box.

Poor thing was apparently "holding it" for several hours not knowing whether to use the unfamiliar box or not. She was crying, and we didn't see any signs of her going anywhere she shouldn't, and finally out of desperation, she must have finally given in (when we were asleep). She definitely doesn't like to be "watched" while she goes, but she's definitely using the middle of the box now, and there've been no out of box accidents. The box didn't require nearly as much litter as I thought it was going to.

We did that for one of our large Himalayans back in the 80s--underbed plastic storage bin--we dubbed it the "handicapped stall." :smug: