Updated at 5:07 p.m.
The office of U.S. Rep. Jesse Jackson, Jr., said Thursday that the Chicago Democrat's medical condition is more serious than staff initially thought or believed.
"Recently, we have been made aware that he has grappled with certain physical and emotional ailments privately for a long period of time," an emailed statement said.
It said Jackson is being evaluated and treated at an in-patient medical facility, and his doctors believe he will be there for an extended period of time, followed by outpatient treatment.
"We ask that you keep Congressman Jackson and his family in your thoughts and prayers during this difficult period," the statement concluded.
This is the first update on Jackson's health in over a week, when his staff said he was on medical leave and being treated for "exhaustion."
The once-rising Democratic star has faced accusations that he signed off on a pay-to-play offer aimed at winning a U.S. Senate appointment from ex-Gov. Rod Blagojevich. Jackson has never been charged and has denied wrongdoing, though the House Ethics Committee is investigating.
In addition, the congressman acknowledged a private marital issue.
Long known for a near-perfect voting record in the U.S. House, Jackson has missed more than 70 straight votes.
Meantime, Jackson's Republican opponent in the November election said the public deserves to know more about the congressman's health.
"My heart goes out to him - keep him in our thoughts and prayers for a good, quick recovery," Brian Woodworth said Thursday.
But on the other hand, Woodworth said, Jackson's office is not being specific enough.
"Somebody who had a stroke like Senator Kirk - it's assumed he's going to be out for a long time. Somebody who's having hernia surgery, you're going to be out for a couple days," Woodworth said. "So, for the public to understand what's going on with the representative, I think there's an obligation to be more open. And that's all I'm saying."
The Second Congressional District, which stretches from Chicago's South Side to past Kankakee, is overwhelmingly Democratic.