Ask Dr Bec: Why does your stomach growl when you’re hungry?

Narrabri-based scientist Dr Bec Thistlethwaite contributes a column to The Courier on the science in our daily lives. Readers are invited to send their science questions in to Dr Bec via [email protected]

Why does your stomach growl when you’re hungry?

That embarrassing grrrr from your stomach in a quiet room?

It actually has a name – borborygmus (pronounced bor-bor-RIG-mus) – and it’s totally normal.

But why does your stomach make all that noise, especially when you’re hungry?

It all comes down to your digestive system staying on the move.

Your stomach and intestines are lined with muscles that contract in a wave-like motion called peristalsis.

This helps move food, gas, and fluids through your gut.

These contractions happen all the time – not just when you’re hungry.

But when your stomach’s empty, the growling gets louder. Why?

Because there’s less stuff inside to muffle the sound.

It’s a bit like shaking a nearly empty bottle versus a full one: less contents means more sloshing and noise.

When you haven’t eaten for a while, your brain sends signals to your digestive system to start cleaning up.

These ‘housekeeping’ waves clear out leftover food and get the gut ready for the next meal.

They can start around two hours after you last ate – and yes, they can be surprisingly loud.

Your stomach also releases hormones during hunger that signal your brain: “Oi, it’s time to eat!”

These same signals ramp up peristalsis, creating even more movement – and more growls.

Turns out a rumbling belly isn’t just a cry for food – it’s your body doing important maintenance work and gearing up for your next meal.

And while it might feel awkward in public, it’s actually a good sign that your digestive system is healthy and doing its job.