From: Rabbi Moshe Sofer
To: Rabbi Yosef Yoel Deutsch
A man whose gid was perforated by illness and subsequently healed by physicians sought to know if he bore the status of petzua daka. The Chasam Sofer rules to permit him to marry, reasoning that damage caused by illness is classified as bidei shamayim by most poskim and thus not disqualifying, that the healed perforation restores valid status, and that a sfek sfeika hamishapeich supports leniency throughout. He further validates the doctors' observable testimony under the principle of lo mera umanusto.
Source: Shu"t Chasam Sofer EH I §16