>>939251It would be difficult and uncomfortable to poop like that. Toilet paper is obviously most comfortable but you'd have to pack it out (I do anyway). Alternatively, wet snow is the best because it's easy to clump and washes while it wipes, then comes smooth sticks/thick leaves, then smooth rocks (be gentle), and finally moss, which isn't really that clean but it gets the poop off your butt.
I haven't pooped in conditions with flies, but mosquitos. You can feel them land on your butt and it's uncomfortable. Personally I've always been really paranoid about deer ticks jumping on my butt and not being able to notice.
Hope that answers your questions. Peace.