Today I found out why your stomach growls when you are hungry.

Generally speaking stomach growling, or as the Greeks named it and Doctors call it today “borborygmi” (which is an onomatopoeia), is the noise created during rhythmic muscle contractions in your stomach and intestines.

Your digestive system is one big long tube that goes from your mouth to your butt, with a lot of interesting biological machinery in-between.  How the body gets food through this long tube is accomplished via waves of muscle contractions, called peristalsis, that run a few inches at a time all down your digestive track.  These waves of muscle contractions also serve to mix and churn foods, liquids, and digestive juices together.  The resulting cocktail is called chyme.

The contractions themselves are really not too dissimilar to how your heart beat works– fluctuation of electrical potential in the smooth muscle cells which causes the muscle to contract in a rhythmic fashion, in this case called the “Basic Electrical Rhythm” or BER.  This rhythm is about three times per minute in the stomach, and 12 times per minute in the small intestines.  The sound you are hearing when your stomach and intestines make noise is the result of these muscular contractions mixing and moving the chyme along, as well as pushing any resultant air through your system.

So why does your stomach seem to growl more when you are hungry?   When your stomach and intestines are empty, it triggers a reflexive generation of contraction waves, even though there isn’t really much of anything in your stomach that needs moved along.  These are meant to clear out all of your stomach contents, including the mucus, any remaining food, bacteria, etc.  It’s your body’s way of doing a little house cleaning, making sure no food or other matter is accumulating anywhere along your stomach or intestines.  It’s typically this that you are hearing when you’re hungry.

You might be asking yourself, “Well if my stomach is doing these contractions even when I’m full, moving food along, why don’t I hear them all the time?”  To answer that, think of the stomach as hot water bottle.  When it is full and you slosh the contents around, there is little to no noise, depending on just how full it is.  The less you have in it, the more noise the sloshing makes.  This is pretty much exactly what is going on with the stomach, except the muscles lining the walls of your stomach and intestines are doing the sloshing as they push the contents of your stomach and intestines towards your derriere.

So how does one avoid stomach growling when, say, you are in a quiet classroom taking a test in school or a quiet open office space?  The best tip, of course, is to eat something.  But to do this relatively continually without over eating, one needs to eat a series of small meals throughout the day instead of a few large ones.

For those of us who stick to the few “big meals” way of eating, though, in order to avoid the sometimes embarrassing growling, I’ll share two tricks of my own device; though I’m sure many others out there have discovered these. Both tricks basically accomplish the same thing, but in two different ways.

The first trick is that, when you feel a growl coming on, take something like a pencil and quite literally push it hard into your stomach area (eraser end first of course).  If you push it hard enough, it will literally compress a part of your stomach, giving it much less space to slosh or even stopping it from being able to slosh at all temporarily.  I’ve found just pushing on the stomach area with your hand tends to not work as well.  Something small and thin like your finger or a pencil seems to work better; this is probably to do with focusing on a small surface area and specifically on your actual stomach instead of just pushing your upper belly with your hand which also pushes some of your other organs, so less effective.

The second trick is, when you feel a stomach growl coming on about 10 or 15 seconds before, take a really, really deep breath- as deep as you can.  Then hold your breath until you feel the growl sensation pass.  This effectively does the same thing as the previous method, but from the inside with your lungs expanded pushing down on your stomach and compressing it so that it can’t slosh things about as much.  The “pencil method” works better, but this is a pretty reliable backup and is hands free.

If anybody else has any good tips they’ve figured out on stopping stomach growling in potentially embarrassing situations when you can’t get food or if anybody’s used my above two methods in the past, feel free to share in the comments below.

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