I am not qualified to answer this, but I did once see a similar question asked on Reddit. The best response I saw was from a commenter whose name I can’t remember, else I would credit them.

That commenter said that his infant daughter had required an operation on her rectum. The commenter asked the surgeon how the surgery site could possibly not become infected and was told “the asshole knows how to handle shit.”

That answer seemed reasonable to me and I probably will never forget it.