Sen. Mark Kirk's office announced Monday that the senator, who is still recovering from a 2012 stroke, underwent surgery to remove his gall bladder.

Kirk, R-Ill., went to Northwestern Lake Forest Hospital in Illinois on Saturday with stomach pains. Doctors determined he had gall stones and on Monday operated to remove his gall bladder.

"His doctor expects a quick recovery," Kirk's office said.

Kirk suffered a stroke in January 2012, and spent much of the following year away from the Senate. Since his return in early 2013, the senator has pursued legislative initiatives to improve medical care for those undergoing stroke rehabilitation. The Illinois Republican has also pressed Congress to enact tighter sanctions against Iran.

Working on Iran sanctions, Kirk told the Washington Examiner in a November interview, has helped with his mental rehabilitation following the stroke.

“My work is the central driving force behind my rehabilitation,” he said. “I am completely motivated by stopping a war between Israel and Iran, making it unnecessary.”

Kirk is currently “resting comfortably,” his office said.