Jimmy Kimmel's seven-year-old son has undergone his third open-heart surgery.

The 56-year-old TV star has taken to social media to reveal that Billy underwent another open-heart surgery over the weekend.

Jimmy - whose son was born with a congenital heart disease in 2017 - wrote on Instagram: "This weekend, our boy Billy had his third (of three, we hope) open heart surgery. 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 comedian also thanked the "hard-working" staff at Children's Hospital Los Angeles (CHLA).

He said: "Walking around this hospital, meeting parents at their most vulnerable, children in pain and the miracle workers who do everything in their considerable power to save them is a humbling experience. 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."

Jimmy praised his son's toughness, too.

The TV star - who has been married to Molly McNearney since 2013 - continued: "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) 7 year-old we know. (sic)"