A New York dad celebrated the perfect Father's Day with his entire family at their home in Binghamton over the weekend after spending months inside hospitals fearing for the life of his nine-month-old son, Caleb.

He might not have received a special surprise on June 21, but Brian Munn and his wife are just happy to see Caleb on his way to full recovery after he underwent surgery last March when Brian donated part of his liver to him.

"(Caleb is) doing really well considering it's only been three months post-transplant. A lot of people see pictures of him now and actually almost forgotten when you look at him, what he's been through," Brian's 27-year-old wife Brittany told Fox News.

In September, Brittany gave birth to Caleb, who was born with biliary atresia (BA). According to the US Department of Health and Human Service, BA is a rare, life-threatening disease that damages the liver in newborns.

The US health department, the Daily Mail reported, explained that the disease actually occurs when a baby's bile ducts inside or outside of the liver do not have normal openings, causing blockages and inflammation within the liver.

While healthy babies normally recover from BA a few weeks after birth, Caleb was still jaundiced by December, prompting Brian and Brittany to rush him to Montefiore Medical Center in the Bronx.

After Caleb was diagnosed with an end-stage liver disease, Fox News reported that he immediately underwent a Kasei procedure to replace the blocked bile ducks with parts of his own intestine.

However, Caleb had to endure a five-hour drive in the middle of a snowstorm back to Montefiore, where doctors discovered that the surgery failed and that the baby would need a transplant.

"Doctors told us if he was not able to get a transplant, that he would have died by the age of two. That was a really hard pill to swallow," Brian said in another interview.

But since Brittany, who is the perfect match for Caleb's blood type, was not yet able to pass six months postpartum, the Munns had a hard time looking for donors until doctors encouraged Brian to donate a part of his own liver.

Brian, who has a different blood type, was ready to hop on the operating table as soon as he learned that children under the age of one can still undergo organ transplants from any blood type.

Dr. Milan Kinkhabwala, chief of Einstein Center for Transplantation's division of transplantation at Montefiore Medical Center, explained that infants below 1 year have yet to develop antibodies that can reject a new liver.

This means, Kinkhabwala pointed out, doctors can perform an incompatible transplant. To prevent rejection of antibodies in the future, Caleb would need to take a special medication in the form of rituxan.

After undergoing surgery to put a part of his liver into his infant son on March 20, Brian recovered immediately while Caleb had to go under the knife to address some complications.

In an interview with WBNG, Brittany said Caleb now weighs 20 lbs., can roll on the floor, and has been doing pretty well three months after surgery.

The mother of three children was proud to say his youngest son is now down from 15 medications to nine.