Ryan Stiles: Brave Drew Carey Star's Medical Crisis

Funnyman Ryan Stiles' double duty as the star of Whose Line is it Anyway? and The Drew Carey Show has him doubled over with excruciating back pain, say sources.

It's so bad that sources say Stiles, who plays Carey's buddy Lewis on the sitcom and an improvisational comedian on Whose Line?, is facing a medical crisis: Should he have back surgery? Or will it only make things worse?

"Ryan has had a lot of pain from his back most of his life and it's becoming intolerable," says a source. "But he's really scared about what an operation might do to his back."

Working 12-hour days, seven days a week has taken a toll on the gangly 6-foot-5 comic.

Stiles, 41, who has two children with his wife Pat, has tried alternative treatments like massage therapy, but nothing seems to work, says the source.

"Drew knows the pain Ryan's in, and he's very sympathetic," says a pal.

Even so, by the end of shooting, Stiles is usually so stiff he's in agony, say insiders. But, courageously, he keeps on going, day after day. Says a pal: "He's going to try to stick it out until Christmas, then decide whether to go under the knife."

***Again, this has NOT been confirmed, please don't believe everything you read... especially that from a tabloid