The appendix must come out — but first the show must go on. Kelly Clarkson might have been all smiles hosting the Billboard Music Awards (May 1), but inside she was suffering.

The American Idol pioneer, 37, revealed she had an emergency appendectomy the morning after the show, following a last-minute flight from Las Vegas, where the show was hosted, to her home in Los Angeles.

A fan tweeted praise for Clarkson’s dynamite stage presence, and two performances, in the face of severe pain, to which Clarkson responded: “I may or may not have broken down in tears after the show from pain.”

The singer gave a shout out to “all the amazing people” at LA’s Cedars-Sinai Medical Center for taking care of her, announcing she is “feeling awesome now!” Clarkson added a quip, “Bye bye appendix #TheShowMustGoOn,” with some sassy emojis for good measure.

The pop star, according to Entertainment Tonight, dealt with appendicitis all week long, but is currently resting before her scheduled return to co-host The Voice live this week. – New York Daily News/Tribune News Service