The singer suffered several ruptured hernias, according to a statement.

“He is under doctor’s orders not to move a muscle for at least eight weeks,” the statement read.

Amen had planned a full month of U.K. dates in May and June leading into a full European tour. The band hopes to be back in action in time for the European leg, and will reschedule the U.K. dates. All tickets bought for the canceled shows will be honored at the rescheduled gigs.

In a post on the band’s Web site, Chaos’ ailment was described as “an old stage injury that has gone untreated for some time.”

“We are all very shaken up right now,” the post said. “This could very well have happened two weeks from now during a show on the tour, and due to the intensity of Amen’s live shows, it would have most likely resulted in the death of Casey Chaos. …

“Casey, in fact, wanted to go ahead with the tour against doctor’s orders, but the rest of the band and I decided that we would not let him go on without a full recovery under his belt.”

The band added that the singer’s condition is a result of a rigorous rehearsal schedule and serves as a “wake up call.”