Ronnie James Dio was in agony as a 2009 tour with the Black Sabbath offshoot band Heaven and Hell continued. He just couldn't figure out why.

His wife Wendy and Dio had already visited a Beverly Hills specialist, where he complained about chronic indigestion. "They tested him for his heart, made him run around and did all these tests," Wendy says in a new interview with the Los Angeles Times.

But the cancer spreading inside Dio's stomach went undetected, Wendy says. So, he left to tour in support of Heaven and Hell's new album The Devil You Know, beginning in May 2009 in Europe.

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"We didn't know it was the last tour at the time," long-time bandmate Geezer Butler said in the Dreamers Never Die documentary. "Before he was going onstage, he'd be like doubled up some nights with terrible pain in his stomach."

The tour concluded on Aug. 29, 2009, at the House of Blues in Atlantic City, N.J. – and Dio never appeared on stage again. That certainly wasn't his plan.

"Ronnie didn't want to take a break," Wendy confirms to Times. In fact, she says Dio had already shipped Heaven and Hell's equipment back overseas in anticipation of more concerts.

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Soon, the pain became too much to bear. Dio got a second opinion from a doctor who suggested a blood test. Cancer was diagnosed, but Wendy says Dio couldn't immediately get an appointment at Houston's well-regarded MD Anderson Cancer Research Center. So, they turned to the Mayo Clinic in Minnesota.

The news was sobering: "This doctor there said, 'There's nothing we can do for you. You should just go home and get your stuff in order,'" Wendy remembers. "It was horrible. We went back to the hotel and cried our eyes out – and then I got a text saying we had an appointment at MD Anderson."

Dio had gotten a late assist from Tony Martell of the T.J. Martell Foundation, who helped secure an appointment at the Texas facility. This time, Dio received a more optimistic prognosis and a treatment plan was put in place. That helped extend his life but unfortunately did not cure the cancer. Dio eventually lapsed into a coma and died on May 16, 2010.

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