CHICAGO – U.S. Rep. Jesse Jackson Jr. was back at the Mayo Clinic for an evaluation Tuesday and possibly a longer stay, nearly two months after being released for treatment of bipolar disorder at the Minnesota hospital, his father said Tuesday.

"I don't know how long he's going to be there," his father, civil rights leader Rev. Jesse Jackson, told The Associated Press.

The hospital confirmed Tuesday that Jackson was back at the facility in Rochester, Minn., for a follow-up evaluation "to ensure he is on the path to properly manage his health." The statement did not say much else.