I have a friend who was in the army and said they had to do 100+km training hikes. No one wanted to have to stop to poo so the first thing they did, before even starting, was to eat the block of cheese from their ration packs. They called it plug cheese.
I need to survive for 3 days without pooping, and eating as little as possible. I can pee, but not very often. It can't take up too much space. What food do I pack?
Please don't ask why I need this....