The President's health.

I am sure the President of the US gets the best medical treatment of anyone in the country.

Does the President get tested for sexually transmitted diseases too?

If he asks to be, yes.

The results, of course, would be confidential between him and his doctor.

Same as anyone else, i.e. not unless he’s showing symptoms or has reason to believe he has one.

/aside: That great bastion of investigative TV, manswers (on SPIKE), had a segment that asserted that it was routine for a Secret Service agent to go collect a Presidential stool sample from the john as a matter of routine health testing for the President. (Don’t recall how often such samples were collected.)

Getting a (presumadely with the President not objecting) blood sample monthly would not seem extreme to me…