Republican U.S. Senate candidate Jason Lewis underwent emergency surgery Monday for a severe internal hernia, his campaign announced.

The surgery was successful and minimally invasive, campaign manager Tom Szymanski announced after the former congressman emerged from the procedure. Lewis' doctors say he will be released from the hospital in a couple of days if he continues to have a positive recovery, Szymanski said.

His aides said his campaign would continue, including a fundraiser and rally scheduled for Tuesday in Minneapolis with Donald Trump Jr. appearing on Lewis' behalf.

Lewis is challenging DFL incumbent U.S. Sen. Tina Smith. He previously represented Minnesota's Second Congressional District.

"Let me assure you that nothing will keep Jason Lewis sidelined in his fight to protect Minnesotans from the radical left's assault on our police officers, economy and our Minnesota way of life," Szymanski said in a statement after the surgery.

Lewis was experiencing abdominal pain and was hurried into an emergency room Monday morning for tests. Doctors determined he had an internal hernia, which could be life-threatening if not treated quickly, the campaign said in a statement.

Before Lewis headed in for surgery, he was optimistic and had been speculating about when he could resume campaigning, Szymanski said. The campaign manager posted on Twitter shortly after the initial surgery announcement that "Jason Lewis is going to beat @TinaSmithMN from the hospital."

Smith tweeted that she and her husband wish Lewis "a successful surgery and a speedy recovery."

Minnesota Republican Party Chairwoman Jennifer Carnahan said in a statement that "we look forward seeing Jason again on the campaign trail soon and will work on his behalf until he returns."

Jessie Van Berkel • 651-925-5044