I have seen a lot of stories online of people getting things stuck in there and doctors having to remove it, even items like cucumbers. I get that an item with a highly irregular shape could get stuck. But if it’s something long and rounded, why can people not just poop it out? Is it because the item isn’t soft enough?
Afaik, your intestines have an involuntary motion called persitalsis that keeps your poop moving, which can sometimes backfire with items that go up the wrong way because it’ll suck them up. Your sphincter also tends to keep shut and it’ll will wrap around items that have an irregular shape. Your intestines aren’t straight but they’re muscles that bend around the items which can trap them. Some items are concave enough, like bottles and jars, that will create a vacuum that keeps them in place. You’ll have a hard time getting anything that’s not soft like feces unless the item has a base that’s wide enough to stop it from traveling past your anus.
Disclaimer: I’m not a doctor and some surgeon will probably tell you more details that I totally missed or got totally wrong.