Prolly hot gas from refried beans and jalapenos working over her hemorrhoids. Trump said it was disgusting.
Very likely that or something similar. I have a few additional ideas:
My top guess is drugs. Maybe not the heavy duty stuff 0vomit takes, but I’m betting she also depends on a drug cocktail to appear as “normal” as possible and they were wearing off and she needed a booster dose.
My second guess is physical exhaustion. Standing up for an hour is probably more work than she’s done in years.
Third guess: stress. More people were watching her answer questions at the debate (unlike her Congressional testimony that people mostly ignored) and she feared that she might say the wrong thing. When you lie constantly, it’s hard to keep track and stay consistent.