Hollywood teenage heartthrob Zac Efron has undergone emergency surgery after a bout of appendicitis. The 20-year-old actor was admitted to Cedars Sinai Medical Center in Los Angeles on Tuesday where he was rushed into the operating room to have his appendix removed. Efron is now said to be out of the hospital and recovering now. His publicist tells TMZ.com, "He had his appendix removed and is recuperating." Appendicitis is caused by inflammation of the appendix and can be fatal if left untreated.