Former Gov. Ben Cayetano was admitted to the Queen’s Medical Center with what is believed to be a bleeding ulcer, his wife announced today.

Cayetano, who is running for Honolulu mayor, experienced symptoms Sunday and went to the emergency room, Vicky Cayetano said. He was admitted Sunday night and preliminary tests confirmed a bleeding ulcer, according to a statement from his campaign.

At a news conference, Cayetano said her husband was to have a procedure today known as an endoscopy, in which doctors use a tiny camera to examine the affected area and confirm the initial diagnosis. Once the ulcer is confirmed, the doctors can decide whether to “staple” it to prevent further bleeding or treat it with antibiotics. Both procedures can be done during the endoscopic procedure, she said.

“It’s not life-threatening at all,” Vicky Cayetano said, adding that doctors expected to be able to treat the ulcer with antibiotics and release him by Tuesday. “From everything we’ve been told by the doctors involved, this is treatable and he’ll be back to his full schedule, we think, by Wednesday.”

Cayetano is facing incumbent Mayor Peter Carlisle and former city managing director Kirk Caldwell in Saturday’s mayoral election. The former governor is the front-runner, according to the Hawaii Poll done last month for the Star-Advertiser and Hawaii News Now.

He is the only one opposed to the city’s planned $5.26 billion rail project.