Representative Steve Scalise had surgery on Thursday to control an infection that led him to be moved back into a Washington hospital’s intensive care unit the day before, the hospital said in a statement.

The hospital, MedStar Washington Hospital Center, which has been treating Mr. Scalise since he was gravely wounded in a shooting on June 14 at a congressional baseball practice, said on Thursday evening that the congressman had “tolerated the procedure well.” Mr. Scalise remains in serious condition, the hospital said.

In its statement, MedStar did not identify the nature of the infection or the type of surgery he underwent. Including his procedure on Thursday, Mr. Scalise has had at least three operations in the past three weeks. Doctors have said he will face additional operations to repair broken bones and extensive abdominal injuries.