When your stomach growls, it’s a sign that your brain is sending a message to your digestive organs to prepare them for a meal.
In other words, after your stomach has been empty for a couple of hours, it begins to produce hormones that ultimately cause a message to go to the brain: “no food here, must eat soon.”
The brain replies by signaling the digestive muscles to do their job of contracting. This contraction is called “peristalsis.” The signals from your brain step up the intensity and frequency of peristalsis in the stomach and intestines, so these organs will be ready to help digest again soon. The signals from the brain also stimulate the stomach and intestines to secrete digestive juices.
So why does our stomach growl? What makes the noise? There’s usually also some gas in your stomach and intestines. The noises come about when that mixture of gas and fluid squirt through a small opening, such as the one that separates the stomach and small intestine.
The medical term for these bowel sounds is “borborygmi.”
Noisy borborygmi isn’t always caused by hunger, though. If the gurgles and growls are really loud, it suggests that there’s a lot of extra gas in the intestines, which might be caused by the nervous swallowing of air, an ulcer, or the inability to absorb certain foods, often lactose in milk. But, in most cases, the sounds in your stomach and intestines are perfectly normal.
If you want to tone down stomach growls, try lying on your back or applying pressure to your abdomen – or just eat something!