Then don't pack food, get some vitamins, you won't die. It's physically impossible I think not to poop if you eat anything at all and I wouldn't recommend forcing a constipation as it can cause you more harm than it's worth.

Canned tuna. It's very dry and almost all protein so most of it gets absorbed by the body and you'll be pooping neat little bricks.

Cogmind. Considering it's an always moving living dungeon where the player isn't necessary the center of attention it's very neat to just watch robots minding their own business around the complex.

Zorbus has gorgeous dungeons too.

I'm sorry for your loss, glad to hear he had a caring family.