Maybe he has acid reflux.

Elton John Blames Tantrums on Creativity
LONDON (Reuters) – Pop star Elton John says he doesn’t mean to throw tantrums — it just comes with the territory of being creative.
John told Britain’s Sunday Times magazine that his behavior had changed since beating drug and alcohol addictions 14 years ago, yet “the rage and the temper are still there … but it’s part of being creative.”
The British superstar, famous for his outbursts, grabbed headlines last month when he cursed and shouted at Taiwanese photographers for surprising him as he arrived at Taipei airport, calling them “rude, vile pigs.”
At a London award ceremony a week later, he launched into a foul-mouthed tirade at pop star Madonna, accusing her of charging fans outrageous prices to see her lip-synch in concert.
“Anyone who lip-synchs in public on stage when you pay 75 pounds ($134) to see them should be shot,” he said.
John, 57, said he was working to rein in his temper.
“I don’t seem to have anger — I have rage. There are still times, especially when I’m tired, when the bad temper and the irrationality come out. And I hate that. Because I’m trying to change it.”
The 30-year veteran of the music business also said he has grown weary of the industry’s excess.
“People slag me off because I’m a larger-than-life character, and that’s part of my thing from the past.
“I’m not happy being in the limelight much. I don’t want to be at every party. I used to love it. I hate it now. My life’s changed.”