Why Your Tummy Growls

The story

You are sitting somewhere quiet. Maybe a classroom. Maybe a library. Everyone is silent, and then, from somewhere deep in your middle, comes a long, rolling GRRRRRROWL. Heads turn. Was that... a tummy?

It was. And here is the twist: that growl is not your tummy begging for food. It is simply the sound of your insides at work, and some of the best growls happen when your gut is doing the housekeeping.

Let me take you inside. When you eat, your food travels into your stomach, and then onwards through your intestines, a long, winding, marvellous tube coiled up neatly in your belly. That tube rarely rests for long. Its walls are made of muscle, and they squeeze in slow waves, pushing everything along the way you might squeeze the last toothpaste along the tube. There is always some gas and liquid in there too, and squeezing gas and liquid through a soft, floppy tube makes noise: gurgles, squeaks, rumbles. Your gut murmurs away through the day, after meals and between them, and mostly it is too quiet to hear.

But a while after a meal has moved on, something wonderful begins. With the tube fairly empty, your stomach and the first stretch of your intestines start a special cleaning shift. Strong, sweeping waves of muscle travel through, pushing the leftovers along and sweeping the corridors tidy to make ready for your next meal. Doctors call this pattern the migrating motor complex, and they have a nickname for it too: the gut's housekeeper. The housekeeper returns in cycles, again and again, while your stomach stays empty.

And that helps explain why some especially noticeable growls turn up when you are hungry. The cleaning waves are strong, and they are squeezing mostly gas and liquid, which is a noisy business. Your belly is not shouting, feed me. A lot of the time, it is humming while it tidies up.

Now, the gift of this story: the growl has one of the best real names in all of medicine. Doctors call tummy rumbles borborygmi. Say it slowly: bor-buh-RIG-my. It comes from an ancient Greek word, and people have been using rumble-words like it for more than two thousand years, because a word for this noise practically writes itself. Say it again and you can hear the tummy inside the word.

So the next time your middle rumbles in a quiet room, there is no need to feel embarrassed. You can simply think: aha, borborygmi. My gut is squeezing gas and juices along, and if I have not eaten for a while, it might well be the cleaning crew, sweeping the corridors ready for the next delicious thing to come along. It is not rude. It is housekeeping, and honestly, it deserves a thank you.