This may well imply that the right to refuse treatment is really a separate right from the right to protect yourself from attack. That's the question to ask. Lumping them together into 'intuitive' labels like body integrity gains little and risks much, as I suspect that you lose much more data than you gain by doing so.
I think the reverse is true. There's a lot lost when you split up "bodily integrity" into the right to refuse medical treatment, the right to refuse consent to sex, the right to not be tortured, the right not to be subjected to involuntary body modification, the right not to be maimed, the right not to be sterilized, the right not to be poisoned, etc. Why not combine these into a single concept of bodily integrity or security of the person?
Lets see:
"The right to refuse consent to sex" - Right of self-defense is directly applicable, obviously violated if it happens anyway.
"The right to not be tortured" - Right of self-defense is directly applicable, obviously violated if it happens anyway.
"The right not to be subjected to involuntary body modification" - Right of self-defense is directly applicable, obviously violated if it happens anyway.
"The right not to be maimed" - Right of self-defense is directly applicable, obviously violated if it happens anyway.
"The right not to be sterilized" - Right of self-defense is directly applicable, obviously violated if it happens anyway.
"The right not to be poisoned" - Right of self-defense is directly applicable, obviously violated if it happens anyway.
"Why not combine these into a single concept of bodily integrity or security of the person?"
I dunno, maybe because the right of self-defense already seems to cover it?
Although I will conceed "The right to refuse medical treatment" can venture into some weird territory, I'm inclined to think a Self-Defense claim can be made there if the person believes the treatment either isn't for their own benefit, or in whatever they consider their own best interests to be(which might be a bit different than continuing to live), although you're going to have a hard time selling the jury on your need to kill the medical staff at the local hospital because they were trying to administer what most would consider a routine treatment. That said, while
the use of force to avoid that particular fate may not be deemed reasonable in that case, it could later be litigated in court and found that your rights were violated all the same.
So in this case, the governments role would be to intervene when your ability to exercise the right of self-defense was insufficient for handling whatever the situation at hand was.