The 66-year-old musician cancelled his summer concert which was scheduled yesterday after being struck down with the medical condition, reported Daily Mirror.
The 'Rocket Man' hitmaker revealed how he had been playing through pain and could have died any time.
"I was a ticking time bomb. I guess I could have died at any time. I feel so lucky and so grateful to be alive. I played nine gigs and the White Tie and Tiara Summer Ball in agony," John said.
The singer initially thought he had food poisoning but medical examinations revealed it to be a potentially-fatal appendix abscess.