Jimmy Kimmel fought back the tears as he appeared on his talk show with his seven-month-old son - just days after the youngster underwent heart surgery.

The 50-year-old TV presenter returned to his show 'Jimmy Kimmel Live!' after having some time off last week while Billy went under the knife, and he held his son in his arms while hosting the first part of the programme and admitted the tot is ''doing great''.

He said: ''I was out last week - because this guy had heart surgery. But look he's fine everybody. He may have pooped but he's fine.

''Daddy cries on TV but Billy doesn't - it's unbelievable.

''Billy's doing great. He has one more surgery. He had an operation a week ago, they say he's probably on track to win at least a bronze medal in the Olympics in 2036.''

Jimmy thanked Chris Pratt, Tracee Ellis Ross, Neil Patrick Harris and Melissa McCarthy for guest hosting the show last week and taking time out of their ''very busy lives'' to allow him to have some time off.

He said: ''I'm grateful for them for doing that.''

Jimmy - who has kids Katie, 26, and Kevin, 24, with former wife Gina, and three-year-old Jane with wife Molly McNearney - also paid tribute to the ''very bright and talented'' doctors and nurses who looked after Billy in hospital and told viewers about a health insurance programme.

He said: ''We want to thank the very bright and talented doctors and nurses at Children's Hospital who treated Billy and many kids with so much care and compassion--children from every income level whose health is especially threatened right now because of something you probably never heard of. It's called CHIP [Children's Health Insurance Program].

''Parents of children with cancer, diabetes and heart problems are about to get letters saying their coverage could be cut off next month. Merry Christmas, right?

''This is literally a life and death programme for American kids. It's always had bipartisan support, but this year, they let the money for it expire while they work on getting tax cuts for their millionaire and billionaire donors.''

Last week, Jimmy's wife Molly praised him for speaking out about his son's life-threatening condition on his show earlier this year when he revealed Billy had been born with a congenital heart defect, and had to undergo open-heart surgery when he was just three days old.

She said: ''I sobbed through the entire thing. I couldn't believe the strength that it took to tell that story a week after it happened. He didn't have to do that. Our family has excellent health care; he had nothing to gain from that. He did it for the other people whom we met in that hospital. He came home that night, and I just hugged him and I wouldn't let go.''