High School Musical star Zac Efron has undergone emergency surgery to remove his appendix, his publicist has said.
The 20-year-old actor had the operation at Cedars-Sinai Medical Center in Los Angeles, according to Gina Hoffman.
He was taken to hospital a day after Disney confirmed he was to appear in High School Musical 3: Senior Year.
Efron became a teen heart-throb as Troy Bolton in the surprise hit Disney TV movie when it was first screened in January 2006.
About 17.2 million people in the US tuned in to see the sequel of the song-and-dance spectacular in August 2007.
Its success has spawned soundtrack albums, a concert series, ice skating tour and a Broadway-style show.
Efron will be joined by co-stars Vanessa Hudgens, Ashley Tisdale, Lucas Grabeel, Corbin Bleu and Monique Coleman in the next instalment of the series.
The film will see the stars as high-school seniors staging an elaborate musical before they graduate.
Filming is scheduled to start in the spring and will be released on 24 October.