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Days after he was hospitalized for a gastrointestinal disorder, Josh Hartnett is back home, his rep tells Usmagazine.com.

"He has had a lot of testing," publicist Susan Patricola tells Us. "They released him, and they are trying to figure out what it might be. He is fine."

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Hartnett, 30, was taken to Cedars-Sinai Medical Center in Los Angeles at 1:45 a.m. Sunday after suffering a "flare-up" of an ongoing gastrointestinal problem, his rep said. The condition also plagued him while he was starring in London in the stage version of Rain Man.