One time I had black stool, but it turned out it was just because I'd eaten an entire box of oreos

Had beets last night and eveytime I get a heart attack after pooping

It fucking sucks how unusable the internet has become for that sort of thing. Reddit swept up all the old forums, monopolized that kind of community discussion-based information and then completely enshittified it. Maybe I shouldn't say "completely" because they're still in the process of making it worse.

I hope you were able to eventually find information that satisfied you, but in case you didn't already see this elsewhere, it's not color alone that should necessarily be cause for concern, it's also consistency (and by that I mean texture, not regularity). If it's black but normal shape and texture for you, like many others here have said, it's reasonably likely just a matter of something you ate (like the chips you mentioned). However, if the consistency is also abnormal for you, especially if it's really tarry (black tar) then that may warrant telling a med professional irl about it.

I get that from blueberries, spinach, kale and or red wine. I've had a really nice salad and wine one time and it looked like sauron's fingers

It could be from iron supplementation, if you recently took nutritional iron. Mostly these things are idiopathic. If you have a secondary symptom or it lasts, go to urgent care asap.

has layers of advice hell, and one of the deepest is /r/getmotivated. It's just a place for rage filled nerds to LARP as Tyler Durden while Tyler Durden is LARPing as a drill sergeant.

If you ate blueberries, that can cause your dump to be very dark. (speaking from experience)

Even my hobbyspace subreddits are going to shit and that was my justification to keep using it.