(FORTUNE Magazine) – The most famous gastrointestinal urban legend involves that whopper about Pop Rocks candy and Coke, but the runner-up is chewing gum. Schoolchildren have long been warned that if they swallow a piece of Hubba Bubba, it will stay in their stomachs for anywhere from two to nine years--depending on the playground they frequent. Is this story for real? What really happens to all of the gum that you've swallowed?

Don't panic. You will not go to your grave with today's Trident, Bubblicious, or Big Red in your belly. According to the Wm. Wrigley Jr. Co., makers of Doublemint and Juicy Fruit, ingested gum simply passes through your digestive system like any other bit of roughage. David Schreiber, a gastroenterologist in Providence, says that the insoluble gum base, which gives each stick its chewable properties, prevents gum from being absorbed into your body. Instead, it's simply excreted in a day or two.

"I'm not aware of any reports of [swallowed] gum causing a problem," Schreiber says. Still, it's not a good idea to be snacking on a Plen-T-Pak to get some extra fiber. It might not gum up your system, but that doesn't mean it's meant to be eaten.

--Reed Tucker