Jeff Johnson, the Republican-endorsed candidate for governor, underwent surgery Monday morning at Maple Grove Hospital to repair a perforation in his stomach.

His campaign reported he was resting at the hospital with his family. Earlier, he went to an urgent care clinic with abdominal pain, where doctors determined he needed surgery.

Johnson, 47, a Hennepin County commissioner and former legislator from Plymouth, is one of four Republicans running in the Aug. 12 primary for governor. The others are businessman Scott Honour, former House Minority Leader Marty Seifert and former House Speaker Kurt Zellers.

The winner of the primary will take on Gov. Mark Dayton in the November general election.