To receive a clean bill of health is to be declared healthy, satisfactory or in upstanding condition.
"After two weeks recovery, my doctor gave me a clean bill of health."
This idiom actually originates in the 19th century, when travel abroad was done by ship. Before a ship was allowed to dock, the city of arrival would send health inspectors on to the ships to make sure there were no communicable diseases among the passengers.
If the inspector found the ship free of disease, he would give an official document called a "bill of health" to the ship's captain, who was then free to dock.
Similarly, some etymologists say that the "bill of health" was issued to the captain of the ship prior to departure to certify that the port of origin, rather than the ship, was reporting no epidemic when the crew set sail.