Let your flatulence fly, scientists urge passengers

Flying increases flatulence, according to an article published Friday in the peer-reviewed New Zealand Medical Journal, and passengers should release the gas -- or risk painful medical consequences.

Lead author Dr. Jacob Rosenberg, professor of surgery at the University of Copenhagen, said he always wondered why he had more flatulence flying than when on the ground. Then, after a recent trip, he opened his bag and noticed a water bottle "almost smashed by the change in ambient pressure," said Rosenberg. "And then I thought of the mechanisms of increased bowel air volume when flying."

It's simple. When altitude increases, pressure decreases. According to the thermodynamic principal known as the "ideal gas law," as pressure drops, volume increases. While cabins are pressurized to compensate, the mechanisms can only do so much. When the plane is at a cruising altitude of 33,000 feet, inside it's still the equivalent of 8,000 feet above sea level. That's a lot of physics bearing down on your intestines.

There's a clear medical rationale for releasing the gas. Holding back flatulence can lead to "discomfort and even pain, bloating, dyspepsia and pyrosis," according to the article, titled "Flatulence on Airplanes: Just Let it Go," which surveyed previously published research and studies. It also notes that holding back flatulence has been suggested as a major risk factor for diverticular disease, a condition where pouches develop in the wall of the colon.

But just try telling that to your seatmate.

Instead, Peter Post, a director at Emily Post institute and author of "Essential Manners for Men," recommends that travelers "hold it in until they have the opportunity to get up and release the gas in the restroom."

If you can't get to the lavatory in time, for instance, if there's turbulence and the fasten seat belt light is on, "be as discreet as possible" and release the gas, said Post. "People understand the situation and let it go."

Unfortunately, no graceful phrase or gesture exists to completely smooth over the social awkwardness of releasing your personal flatulence inside a confined space where 50 percent of the air is recirculated. An "excuse me" can really only go so far. It can even draw its own unwanted attention.

"Almost anything you say can create embarrassment and make the situation more difficult," said Post. "Your best bet is to keep your mouth shut."