In an era where most rock bands are about as edgy as the latest Ark Music Factory teen-sensation-in-a-box, Tennessee hell-raisers Kings of Leon have often stood out as a throwback to a messier era.

The band of brothers (and cousin) raised by a Pentecostal preacher rose from humble beginnings to their current status as one of the biggest rock bands on the planet thanks to dark, moody songs, good genes (and jeans) and a well-established reputation as boozing, brawling ladies' men who've been only somewhat tamed by rock stardom.

In recent times, it seemed as if those hellion days were behind them, as one by one the Followill boys have gotten engaged, married or into serious relationships and talked about dialing back the partying.

Questions were raised, though, over the weekend when the Kings announced they were canceling the remainder of their U.S. tour due to singer Caleb Followill's "vocal issues and exhaustion." The news came after a disastrous show in Dallas during which Followill repeatedly complained about the heat and abruptly left the stage, at one point telling the crowd, "I'm gonna go backstage and I'm gonna vomit. I'm gonna drink a beer and I'm gonna come back out and play three more songs." Though Caleb never returned to the stage, frustrated bassist Jared Followill later tweeted, "There are internal sicknesses & problems that have needed to be addressed. I can't lie, there are problems in our band bigger than not drinking enough Gatorade." The missive clearly made it seem as if some deeper issues than the heat were afoot.

Looking back at interviews the band has conducted over the past few years, it's clear that alcohol has long been a part of the fuel that helped the band navigate their rise to stardom — for good or ill. Whether it's Jared jokingly telling MTV News that he was impressively good at "Rock Band" while drunk or Caleb suggesting that the band's most recent CD, Come Around Sundown, "sounds better with a cocktail," to which Jared replied, "Everything [is better with a cocktail]," the boys have not shied away from discussing their tippling. An April 2009 cover story in Rolling Stone magazine called "The God-Fearing, Booze-Swilling Rise of America's Hottest Band," in fact, opens with Caleb and brother drummer Nathan arriving home late one night in 2007 after a heavy night of drinking and getting into such a vicious fight that Caleb dislocated his shoulder and Nathan shattered a $7,000 mirror and then proceeded to repeatedly stab his brother's mattress with a kitchen knife.

The rest of the story has a number of other boozy moments, from Caleb's drunk New York apartment shopping to a description of the light in the interior of their 75-acre Tennessee property "reflecting off the endless bottles of hard alcohol and wine that cover nearly every inch of counter space." It notes that after Caleb met his wife, model Lily Aldridge, he gave up drinking whiskey and now sticks to "wine, beer and the occasional shot of tequila." Though their well-documented love of spirits appears to be at least somewhat to blame for recent troubles, the RS story also mentioned that, like his preacher father, Caleb "suffers from nerves, and he regularly vomits during performances."

Caleb has not made any public statement about what ails him, but on Tuesday, he told TMZ he was focused on healing. "I'm just trying to get better," he said. Asked if the band will still hit the road as planned in September for a string of Canadian shows, he replied, "I don't know ... we'll see how it goes."