Pink Has Her Gallbladder Removed

Pink arrives at the "Happy Feet Two" Premiere on November 13, 2011 in Hollywood, California. Gregg DeGuire/FilmMagic

Pink may have had to cancel her gig performing at President Barack Obama's fundraiser this week, but she sure had a good reason: She underwent surgery to have her gallbladder removed.

"Oh, and P.S….F YOU gall bladder! SAYONARA!!!!!!!!!!!!" the singer, 32, tweeted Sunday, shortly after she was admitted to the hospital for what she believed to be the stomach flu.

Now out of the hospital, the singer is "recovering nicely" from the procedure, her rep tells E! News.

Despite spending multiple days in a hospital bed, the "So What" singer managed to make the most of her recovery time, and even celebrated her and husband Cary Hart's daughter Willow's first birthday at the hospital.

"Happy Birthday to my angel, my purpose, my biggest blessing. I love you Willow Sage," the singer tweeted, along with a photo of her daughter's first birthday treat: a vegan carrot cake confection. "Thanks family 4 bringing my lil girls party to the hospital all weekend for me. I spose it doesn't matter where u r when u eat ur 1st cake!"

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