The singer was suffering from appendicitis when she managed to slay her hosting duties at the star-studded show on Wednesday.
Kelly Clarkson really can do anything!
ET has exclusively learned that the singer had to have surgery to remove her appendix on Thursday, after hosting the three-hour Billboard Music Awards the night before, where she performed two different musical numbers.
Clarkson, who had been suffering from a painful bout of appendicitis all week, flew right home to L.A. from Las Vegas immediately after the awards show and had a procedure the following morning, ET has learned.
The singer is now home resting and recuperating and plans to be back to work on The Voice for their live show on Monday.
Clarkson also responded to fans who tweeted about her surgery, and her amazing job hosting while dealing with the pain, and the singer admitted that she was brought to tears by the experience.
"Not gonna lie.... I may or may not have broken down in tears after the show from pain," she tweeted. "BUT thanks 2 all the amazing people @ Cedars-Sinai I flew home directly after the event, nailed the surgery early this morning, & feeling awesome now! Bye bye appendix #TheShowMustGoOn."
ET has reached out to a rep for Clarkson for comment.
Despite the pain of her condition, Clarkson served admirably as host throughout the night, kicking off the festivities with a fun, musical medley, before returning to the stage later in the evening for a performance of her new song, "Broken & Beautiful."
Check out the video below for a look at some of the star-studded show's most memorable moments.
Kelly Clarkson Belts Out New Song 'Broken & Beautiful' on 'The Voice' Ahead of Massive Elimination
Kelly Clarkson Reveals Which of Her Kids Are Determined to be Famous on 'UglyDolls' Red Carpet (Exclusive)