CHICAGO (CBS) — Congressman Jesse Jackson Jr. has been off the campaign trail and absent from Congress since he was diagnosed with bi-polar disorder in June.

Jackson, who sources say will be returning to the Mayo Clinic for treatment next week, hit constituents with an automated phone call this weekend. It’s the first time anybody has heard him publicly since he took a leave from Congress over four months ago.

In the message, he told residents: “A series of events .. have been difficult to sort through.”

LISTEN: WBBM Newsradio’s Nancy Harty Reports

“For nearly 18 years I have served the people of the second district, I am anxious to return to work on your behalf, but at this time it is against medical advice, and while I will always give my all to my constituents, I ask for your continued patience as I work to get my health back.”

He went on to say that he is “starting to heal” but that doctors said the road to recovery will be a long one.

LISTEN: The Phone Message From Jesse Jackson Jr.

He asked people to be patient as he works to get his health back.

“I am human. I am doing my best.”

“After my family, my constituents are most the important people … I will always act in your best interests.”

Jackson is expected to easily win re-election despite being totally absent from politics for months. He also reportedly is facing a federal investigation over use of his campaign finances.

However, his opponents say it is time for him to go.

One of Jackson’s opponents in the Nov. 6 election, independent Marcus Lewis, says the message to constituents doesn’t address the cloud of federal investigation over Jackson Jr. He said it’s also “too little, too late.”

“This is a sham and it should be rejected outright. We figured he was going to do something like this. We don’t believe a word of it,” Lewis says.

Republican congressional candidate Brian Woodworth said, even if Jackson were showing up to work, he’s no longer effective as the representative of the 2nd District.

“The only power he had was the appropriations power, and now that they’ve done away with the earmark process, he doesn’t have that ability anymore,” he said.

Rev. Anthony Williams said people in the 2nd District need a change.

“People need stability, and people need someone who has maturity, and the expertise to lead that district,” he said.