Jessie J "not OK" after emergency operation.

She’s in hospital.

The woman with a big voice who judges other people with voices on talent show The Voice has been rather quiet on the cause of her recent illness.

She made her debut on Aussie TV last night as the talent show’s new judge, but in reality, things aren’t so shiny.

Brit singer Jessie J, 27, was admitted to hospital last week and underwent an operation for an undisclosed condition.

As is de rigeur for pop stars and most other people with a smart phone, she has documented her hospital stay with Instagram pictures, but she hasn’t said what’s up.

“I am not ok… I am in a lot of pain,” she posted along with a picture of her arm stuck with needles from a drip.

She added that she’s working with doctors on her recovery.