Jimmy Kimmel reveals son, 7, had third open heart surgery

Jimmy Kimmel has spoken out online about his son Billy undergoing his 'third open heart surgery'.

The late night TV show host's youngest child, seven-year-old Billy, underwent his third open heart surgery over the weekend (25-26 May).

In a post to social media, Kimmel explained the family 'hope' it's Billy's final surgery of that kind and took a moment to reflect on the experience.

Kimmel took to Instagram yesterday (28 May) to share a picture of his youngest child - who he shares with writer and producer Molly McNearney - in a hospital bed sporting a beaming smile.

The caption reads: "We went into this experience with a lot of optimism and nearly as much fear and came out with a new valve inside a happy, healthy kid."

The TV host went on to name and thank some of his son's doctors, led by 'the brilliant surgeon Vaughn Starnes, cardiologist Tim Casarez and the excellent, hard-working staff, doctors, nurses and nurse practitioners at CHLA, including, but certainly not limited to Misty, Ann, Sylvia, Dana, Caleigh, Nick, Bekah, Julie, Kenny, Caroline, Lisa, Stephanie, Ellize, Ivy, Pam and Carrie', who he says 'came through for [the family] with immeasurable kindness and expertise'.

Jimmy Kimmel's youngest son underwent his third open heart surgery over the weekend (Instagram/ @jimmykimmel)

Kimmel noted what a 'humbling experience' it was to walk round the hospital meeting other parents 'at their most vulnerable' with 'children in pain' and the 'miracle workers who do everything in their considerable power to save them'.

"We hope you never need CHLA, but if you do - know that they help families regardless of their ability to pay, thanks largely to the Affordable Care Act (another salute to the late Senator John McCain), generous donations from companies like Disney, which I am proud to work for and especially from generous people like you," he added.

The TV host resolved: "Thank you Dr Paul Viviano - my family and I are so grateful to have you in our city and in our lives. Thanks to those loving strangers who took time to pray for and send positive energy to our baby, thanks to our family and friends for rallying around us to an almost-ridiculous extent, thank you to my wife Molly for being stronger than is reasonable for any Mom to be and Billy, you are the toughest (and funniest) seven-year-old we know.

"There are so many parents and children who aren’t fortunate enough to go home after five days. Please share your love, hearts and prayers with them and if it moves you, support @ChildrensLA (link in bio) or a great children’s hospital near you (@CMNHospitals).

"Nothing matters more than taking care of each other. With love and gratitude, Jimmy."