Stomach growling

How it works

The wall of your stomach and intestines is made of smooth muscle. This muscle squeezes in waves. Each wave pushes the contents a little further along. The movement is called peristalsis⁴.

The gut always holds some gas and liquid. When a wave squeezes gas and liquid through a narrow section, the mix gurgles. That gurgle is the growl. Doctors call the sound borborygmi, from a Greek word that probably imitates the noise¹. Doctors listen for it with a stethoscope and call it bowel sounds.

The noise does not mean you are hungry. It happens all day, after meals too. A full stomach muffles the sound. An empty stomach is a hollow chamber with gas in it, so the same wave sounds much louder¹.

An empty gut also runs a special program. A few hours after a meal, once the stomach is empty, a strong wave starts in the stomach and sweeps down through the small intestine². It is called the migrating motor complex. It clears out leftover food and bacteria². The hormone motilin helps start these waves²³. These sweeps repeat until you eat again, so an empty stomach growls in bursts.

Ghrelin, the hormone that makes you feel hungry, is made by the stomach when it is empty¹. Loud growling and hunger both happen when the stomach is empty, so they often arrive together¹.

Is it a problem?

No. Growling is a sign that the gut is moving as it should. You can often make the sound quieter for a while by eating or drinking something⁵.

Mention it to a doctor if loud growling comes with:

• belly pain,
• bloating,
• diarrhoea or constipation.

Rarely, noisy digestion with these signs points to a digestive disease¹.