Updated 07/09/12 – 3:21 p.m.

CHICAGO (CBS) — U.S. Sen. Dick Durbin says he wishes U.S. Rep. Jesse Jackson Jr. the best, but the congressman needs to let his constituents know more about what has forced him to take a medical leave for almost a month.

WBBM Newsradio’s John Cody reports Durbin said his heart goes out to Jackson and his family as the South Side congressman is treated for unspecified medical and emotional problems.

“He’s clearly going through a very difficult time. I don’t have any inside information about his medical situation. If there is some medical necessity for him not saying more at this moment, then I will defer to that, but he will soon have to make a report on what he’s struggling with – the physical condition he’s struggling with,” Durbin said.

LISTEN: WBBM Newsradio’s John Cody reports

The senator said Jackson Jr. should tell his constituents “soon” why he’s taken a leave of absence from the House of Representatives, although he did not specify how soon.

Jackson spokesman Frank Watkins declined to comment on Durbin’s statement Monday afternoon.

The congressman’s office announced on June 25 that he had been on a leave of absence since June 10 due to “exhaustion.”

Last week, Watkins said Jackson’s medical condition was more serious than first believed.

“Recently, we have been made aware that he has grappled with certain physical and emotional ailments privately for a long period of time,” Watkins said in an email last week.

The congressman is being treated at an undisclosed “in-patient medical facility” and his doctors have said he “will need to receive extended in-patient treatment, as well as continuing medical treatment thereafter.”

Jackson’s representatives, however, have not yet said where he is being treated, or what specific ailments he is being treated for.

Durbin said Jackson’s health “is the number one priority.”

“As a public official, though, there reaches a point where you have a responsibility to tell people what you’re facing and how things are going,” Durbin added.

Durbin suggested Jackson should follow the example set by U.S. Sen. Mark Kirk, who has been out of action after suffering a stroke in January. Kirk’s office announced his stroke two days after it happened, when Kirk went to Northwestern Memorial Hospital for surgery.

Kirk’s doctors also provided regular updates on his condition in the days after the stroke. About three months later, they released a photo of Kirk during his rehab from the stroke, then later released a video of him talking about learning to walk again.

“I thought Senator Kirk’s video talking about his rehabilitation answered hundreds of questions that I was facing, and – I think, to the satisfaction of Illinois voters – told them what his current situation is, and what his hopes are about recovery,” Durbin said.

Jackson’s office has not said how soon he is expected to return to work.