I'll try to explain my reasoning:
A child has a medical problem, and they're going to get a surgical fix for that medical problem, and the asker is asking here for advice about dealing with that medical problem and surgical solution.
That is clearly undeniably asking for medical advice. Asking for medical advice while saying "I'm not asking for medical advice" doesn't mean that you're not asking for medical advice. The correct answer should be "ask your doctor".
See, for example, Reddit's /r/AskScience information about what is or isn't medical advice:
1.) If your question includes the words “Me, I, or My”, and asks about the human body, then you are asking for medical advice. By including
the reference to you, any answer is, by definition, giving you
information about your own personal medical status. That, my friends,
is medical advice. For those of us who are medical professionals,
answering the question can open us up to issues with liability, even
if the question is something as simple as “Why do I have hair on my
head”. I realize it may seem trivial, but a simple re-wording to “Why
do humans have hair on their heads” COMPLETELY changes the question to
something we can allow.
2.) If you’re asking about something related to the human body that you experience, that the majority of other human beings do not
experience, then you are asking for medical advice. If it isn’t
something normal, go see a doctor. We cannot diagnose you, even if you
think it’s not something serious. I recognize many of you are just
looking for some extra information about an “oddity”, or maybe even
trying to decide whether you should go see a doctor, but that is not a
service we can provide. Besides the fact that it can be illegal for
some of us to answer your question, you shouldn't trust this type of
thing to strangers on the internet.
3.) Asking about "a friend", family member, celebrity, or even the homeless guy down the street is still medical advice. Just because it
isn't about you, doesn't change it from being medical advice. If you
are asking about a specific individual, it's off limits.
4.) Adding a clarifier at the end of your post like, “I’m not asking/looking for medical advice”, does not change the fact that you
ARE asking for medical advice. We get hoards of posts like, “I have
this weird burning sensation when I pee, what could it be? Oh, by the
way, I’m not looking for medical advice.” Yes, yes you are looking for
5.) Posts that provide any recommendations to an individual about their body, diet, medical/psychological status, et cetera, are
considered giving medical advice, and are not allowed.
Now, that's Reddit, not here, and they're very different sites. Do we want to be less responsible than Reddit?
The fact that you can find a bunch of other medical questions that haven't been closed just shows either that moderation is inconsistent (fair enough; different volunteers do it across different times and community feeling changes) or that I'm wrong and there is no ban on medical questions here and anything goes, have at it, oh and hey can you identify this rash?
If you're arguing that medical questions shouldn't be banned, well, go ahead in a new meta question. That's the de facto state anyway and there's some support for that position.