Nothing the OP said made it seem like they were fine pooping in the street. If anything it’s pretty clear they don’t think it’s acceptable. They just don’t think it’s a medical issue. You’re insisting that it is, but you’re not their friend and you’re not a doctor and you don’t have medical training in identifying what is normal and abnormal bowel behavior. That’s being a weirdo because you’re crossing a social line here. Even if you personally think it is, you’re not in a social position where your insistence isn’t incredibly rude.

Several people are telling you to chill out/back off not because it’s acceptable to shit on the street, but because it’s not acceptable to insist on the health status of someone without first establishing either rapport or appropriate relevant knowledge that justifies breaking a social boundary. You have no justification, so your suggest was a little nosey, and your insistence is flagrantly rude.