Bret Michaels Bret Michaels

Bret Michaels is "doing well" after undergoing an emergency appendectomy, his rep said in a statement.

The rocker and current Celebrity Apprentice contestant was rushed into surgery in San Antonio at 1 a.m. Monday after suffering severe stomach pains and what was assumed to be the flu all day Sunday. Doctors later determined the singer had acute appendicitis.

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"According to doctors, Michaels, who remains in the hospital, is doing well and beginning the recovery process," the statement read.The surgery forced the 47-year-old to cancel his Sunday performance at Sea World, which has since been rescheduled for Oct. 1.

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"Michaels, who has been known to perform under extreme conditions that would make most performers cancel, will unfortunately have no choice but to reschedule some of his April tour dates," the statement continued.The new dates will be posted on

his website in the coming days.