New Jersey Sen. Frank Lautenberg is expected to return to work soon after being hospitalized for bleeding ulcer

An ambulance took the 86-year-old Democrat from his Cliffside Park home to an undisclosed hospital Monday evening after he became lightheaded and fell, said the spokesman, Caley Gray.

Lautenberg remained hospitalized tonight after undergoing an endoscopy, Gray said. No discharge date has been set, he said.

Bleeding ulcers are one of the most common reasons patients 70 and older are admitted to the hospital, said Robert Spira, chief of gastroenterology at Saint Michael’s Medical Center in Newark. They are usually a side-effect of aspirin or anti-anthritis medication.

An endoscopy is used to make an official diagnosis. A flexible tube attached with a camera is passed down the patient’s throat to see where the ulcer is located and how badly it is bleeding, Spira said.

Upper gastrointestinal bleeds are rarely fatal among older patients, he said.

"Barring any complications, (the senator) will be absolutely fine," Spira said.