Avicii has been forced to miss a performance after having his gall bladder and appendix removed.
The Swedish DJ had been due to appear at Ultra Live Festival in Miami, but had to cancel so that he could undergo the surgery.
He tweeted to let his fans know what the problem had been: " My fans know that I have had issues in the past with my stomach and pancreatitis...
"I woke up on Wednesday morning with serious pain but I flew to Miami anyway, hoping that it would go away. The pain was still there when I landed so I went straight to hospital. I was treated and left later that night.
"Unfortunately, the pain came back yesterday afternoon and I returned to the hospital where they admitted me to stay overnight."
The Wake Me Up star continued: "My doctors have decided to operate and remove my gall bladder tomorrow morning.
"It's a routine procedure and all going well, I expect to be fully recovered and back on my feet in time for my US True Tour."
Later, Avicii updated his followers with a photo of his arm hanging over the side of a hospital bed, captioned: " Turns out I had a ruptured appendix on top of my sick gallbladder... both were removed during the operation.
"Now I feel like s*** but at least I'm on the road to recovery..."
Madonna recently revealed that she would be working with Avicii on her new album.