I took a bunch of friends camping. They were all beginners and they had never camped before, and one girl ate a ton of bananas before the trip because she thought that would have prevent her from having to go to the bathroom the whole time we were out there, and it didn't work. Bananas don't do that. I think processed cheese does that if you want to give it that a try. But I think better than that is facing the fact that you're going to have to poop while you're camping and here's just some tips that I think will make it a little easier.
First I used bug spray. I just like to spray myself down to make sure there's no visitors while I'm out there exposed. Another thing I like to do is to bring something that makes digging the hole easy and a little garden trowel. It's great. It's light. You can tie it to the back of your backpack. There's also cathole shovels. They fold up, they're light too. You just want to bring something that makes digging the hole really easy and really quick because you want to be in and out of there.
Another thing to bring along is baby wipes. When you're camping, you're not going to be able to shower and you want to feel clean and baby wipes are just really good for having to poop in the woods.
Finally, I think my biggest tip is to do anything you can to make sure it happens easily because you're going to be all scared and your body is going to be eating things that it's not use to, so already your stomach may be acting funny and not normal. So, I like to eat raw vegetables, drink a lot of coffee. You kind of want to do what you can to make sure when the time comes, you're totally ready and it's quick and painless.