This research wasn’t “designed to test the causal relationship between bowel movements, the gut microbiome and cognitive health, so we cannot firmly draw conclusions regarding the precise causal sequence underlying this association,” Ma said.
They believe it might have to do with medication side effects, gut biome, fiber intake, and exercise frequency all of which influence your frequency.
In the beginning of the migration there was a guy that asked for help on how to not poop for 3 or some days and would not tell anyone why, this sparked a bunch of memes, I don't have any to link but they should be easy to find if one is interested.