Kacey Musgraves quietly underwent surgery to remove her gallbladder last year.

The Space Cowboy singer went public with her health issue in a Twitter post early on Thursday, as she tried to kickstart a social media trend, calling on her followers to share the "weirdest" photo on their phones.

Kacey revealed she had been hospitalised 12 months ago as she posted her own graphic snap, which featured her organ laying on a piece of fabric, although she offered up no other details.

"Weirdest pic in ur phone right now: go!" she wrote. "Ok since no one asked mine is of the s**tty gallbladder that had to be taken out of my body exactly a year ago. Isn't science neat (sic)".

Kacey had a tough 2020, as in addition to her operation, she also split from her husband Ruston Kelly, with them filing for divorce in July.

In a recent interview with Rolling Stone magazine, she explained that their marriage "just simply didn't work out."

"It's nothing more than that. It's two people who love each other so much, but for so many reasons, it just didn't work," she explained. "I mean, seasons change. Our season changed."