It looks like the original post is gone, but there was a guy 2.5 years ago who asked how to avoid pooping for 3 days. It generated a lot of buzz and was the first big insider meme that appeared on Lemmy to my knowledge.

https://lemmy.world/post/616615

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? - Lemmy.world

lemmy.world

Please don’t ask why I need this. It would be great if the food also made me sweat less. It has to be something I can easily find. EDITS FOR CLARIFICATION: - I am not planning on partaking in any illegal activities. - I do not condone the use of illegal substances and am not planning on smuggling anything anywhere. - I am not going on a hiking trip or mailing myself anywhere. - I will be staying in a tent (not a small one; a huge with with air conditioning and everything). I will be traveling for five days, returning to my current location on day 3 and traveling again on the last two days. I will not poop on the first three days (hopefully). - Clean toilets with all the expected facilities will be available to me. I am not going to poop for reasons that I wish to keep to myself. - If it gets bad, like really bad, like a-piece-of-poop-is-literally-halfway-out-my-ass bad, I will use the toilets. Please stop asking because I am not telling anyone the reason.