Brian Munn donated part of his liver to his 9-month-old son, Caleb, for a successful operation to combat his son's end-stage liver disease, which was diagnosed just three months after his birth.

Caleb was born with biliary atresia, which affects liver function by blocking crucial bile ducts. After three months, the newborn showed signs of suffering and already needed intensive medical attention.

"I guess I was kind of anticipating [the diagnosis], just with the Googling I was doing... but I wasn't expecting it to be as severe as it was, so it was definitely a shock," said Caleb's mother, Brittany, via Fox News.

The family began looking for donors for the transplant and, initially, Brian did not submit an application because he did not have the same blood type as his son. It was after they were informed that blood type does not matter for children below a year old that Brian applied—and they found his liver compatible for Caleb.

Caleb is out of the hospital, in time for the family to celebrate Father's Day. He is now on nine medications a day and will need to be on immunosuppressant medication his whole life, reported Daily Caller.

Family and friends have organized a fundraiser for Caleb's medication.