No matter how good you look in a belly shirt, your innards are hardly a pretty sight. Your gastrointestinal (GI) tract deals with the dirty work of your body: digesting food for nutrients and sending out the trash. This noisy, smelly, squishy system includes the esophagus, a 10 inch-long tube; the stomach, a fist-size bag of muscle; 20 feet of small intestine; and 6 feet of large intestine (aka the colon). With no Google map, we're often left wondering what the holdup (or the rush) is in there and why normally dependable routes suddenly cause trouble. But because of the unappealing issues that arise, talking about your own highway problems isn't as easy as discussing rush-hour traffic. "There's definitely embarrassment, and women tend to suffer in silence," says Jacqueline Wolf, M.D., a women's GI disease specialist at Harvard Medical School. Still, considering that digestive problems — from constipation to acid reflux — affect up to 70 million people, we should muster the guts to find out what's going on beneath our navels.
How long does it take for food to travel through my system?
The majority of the trip averages 24 hours, says Patricia Raymond, M.D., a gastroenterologist in Chesapeake, Virginia. Once a steak hits your stomach, roughly 3 liters of hydrochloric acid begin to turn it into paste. About 30 minutes later, the food sludge travels to the small intestine, which immediately absorbs the nutrients and sends them to your bloodstream. The leftovers move into the colon, where any remaining liquid is sucked out, and they solidify into feces. This detritus takes from 1 to 4 days to snake its way through your colon and into your sewer system, depending on how much fiber your waste contains, says Michael Levitt, M.D., director of research at the Minneapolis Veterans Affairs Medical Center.
Is eating lots of fiber really that important?
Uh, yeah. Fiber is a component of all plant-based foods, such as whole grains, fruits, and vegetables. You don't digest fiber, so it acts like a Brillo pad for the intestines, scrubbing out bad cholesterol and soaking up water so that waste can glide through. Chances are you're not eating enough (the average person ingests only 7 grams daily, though the RDA is 25 — about six servings of fruit or vegetables and two slices of whole-grain bread). To stay regular, beef up your produce intake. Or take a daily 1,500-milligram fiber supplement of psyllium husks, suggests Mehmet Oz, M.D., professor of surgery at Columbia University and coauthor of You: On a Diet. But if you need immediate action, try a laxative with sennosides, stool-softening agents that help liquids mix with the cement in your pipes.
Why does my stomach gurgle when I'm hungry?
"It's very much like the Pavlov's dog effect," Dr. Raymond says. "You see the food, you smell the food, your saliva glands start to go, and your stomach starts to go." That sets off a chain reaction of churning, grinding, and spasms in the intestines meant to help food move through the system. If there's not much in there to move, there's nothing to muffle the noise, so the gurgling is louder. Dr. Raymond compares the effect to the way a partially filled water balloon makes more sound than a full one. But bellies rumble even after you've gorged. Called borborygmi, these are simply the sounds of digestive enzymes and gas moving through the intestines.
Is there any way to avoid farting?
Don't go to Jim Carrey movies.