Clinton won't release information
What else should we expect. Whatever her medical problem is it is definitely serious enough that she cannot come clean, and tell the truth. She just wants you to buy the pig in a poke. Don't be surprised when you get home, and all you have is dross, no pig.
A pig in a poke - meaning and origin.
This all but establishes she has a serious medical condition which merits choosing among the remaining healthy candidates.