CHICAGO — Chicago Police Superintendent Eddie Johnson has left the hospital three days after undergoing a kidney transplant.

Johnson was discharged on Saturday afternoon. On Wednesday, doctors removed a kidney from Johnson’s son and then transplanted into the 57-year-old Johnson.

A day after the surgery, doctors said it went smoothly and that both Johnson and his 25-year-old son, Daniel Johnson, were doing well.

Johnson disclosed in January that he had suffered from a serious inflation of his kidneys for decades and was on a transplant list.

Johnson is expected to be out of the office for three to five weeks.