"Congressman Steve Scalise has been readmitted to the Intensive Care Unit ... due to new concerns for infection," the Medstar Washington Hospital, where Scalise is being treated, announced late Wednesday.
Scalise was shot three weeks ago after a gunman opened fire on a baseball field in Alexandria, Virginia, where he and other GOP lawmakers were practicing for an annual Congressional charity baseball game.
A total of five people, including Scalise, were injured. The 66-year-old gunman, a business owner of Illinois, died in hospital from his injuries after having exchanged fire with law enforcement.
Scalise was shot in his left hip, and the bullet caused some damage to his internal organs. His condition had been upgraded from "serious" to "fair" late last month following surgery.
The hospital said that it will provide a further update on Scalise's condition on Thursday.