I know, but I would expect doctors would, by know, not be so frequently surprised by things lurking in their own bodies.

Not that long ago a never before observed structure every human always had was discovered: https://www.science.org/content/article/scientists-say-they-...

Doctors don't ask about this. People still take Prilosec, and it's acknowledged that it causes cancer. You get what you give: confirmation bias.

Edit: The essential problem is that ranitidine isn't shelf-stable. This could explain some problems with other theraputics which we won't name to avoid downvoting / politics.