It's called a low residue diet https://badgut.org/information-centre/health-nutrition/low-residue-diet/
Sry can't remember. too many new reddits for me to keep track
There is also https://github.com/Not-Quite-RARBG/main
https://therarbg.com/
It's called a low residue diet https://badgut.org/information-centre/health-nutrition/low-residue-diet/