Many of my patients ask me why their stomach growls. Is it just because they’re hungry? Or could it be a sign of something more serious? The simple answer is both yes and no.

What is Stomach Growling?

Stomach growling is the result of a process called migrating motor complex (MMC). MMC is waves of electrical activity that sweep through the intestines in a regular cycle during fasting, causing peristalsis. Peristalsis is waves of muscle contractions that move and push the contents of the digestive tract continually downward, moving along any food, fluid, gasses and air. As all these ingredients get pushed around and broken down into easy-to-absorb pieces, pockets of air and gas also get squeezed and create the noises we hear and call “growling.” Because of this process, stomach growling can happen at any time, not just when you’re hungry. However, if there’s food in your stomach or small intestine, the growling becomes quieter and less likely that you will hear it.

Now, I know what you are thinking – If “growling” is not due to hunger, why are there times in which you felt hungry and heard your stomach growling? This occurs because about 2 hours after you finish eating, your brain gets the signal to start peristalsis again, resulting in the digestive muscles contracting to clear out any food and matter that was missed the first time. As this happens, the vibrations of the empty stomach signal to your brain that you are hungry. These contractions occur approximately every hour, lasting about 10-20 minutes until you eat again.

Can Stomach Growling be an Indicator of a Medical Issue?

Although stomach growling is a completely normal process, there are times in which it could signal something else. Excess gas, stomach bloat and underlying gastrointestinal problems may all be the cause of excessive stomach growling, signaling that your food is not digesting as it should. If you feel that you have excessive stomach growling, you should see your doctor.

For most of us, stomach growling is a perfectly normal function and one that occurs throughout most of the day. It’s just a reminder that your body is always working to keep you in top shape, whether you’re hungry or not!

Written By: Kenneth Brown, M.D.