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LOS ANGELES (AP) -- A spokesman for Jay Leno says the "Tonight" host is doing well after an overnight hospital stay and is expected to be released today.

His publicist, Dick Guttman, said doctors found that Leno's illness wasn't "symptomatic of anything serious." On Friday, Guttman said he couldn't provide details of what ailed Leno when he checked into the hospital Thursday.

The 58-year-old comedian was hospitalized overnight for observation, Guttman said. Leno was expected to be back at work at the Burbank studios on Monday.

NBC canceled Leno's Thursday and Friday shows, with reruns taking their place. It was the first time Leno, who took over "Tonight" in 1992, missed a show because of illness.