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Why does your stomach growl?

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📓 The short answer

Stomach growling is caused by muscle contractions that move food, liquid, and gas through your digestive system. These sounds are amplified when your stomach is empty but also occur during digestion after a meal.

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📚 The long answer

Is it thunder? A dog growling? No, wait, it's your stomach rumbling. To understand why you're able to create such sounds, let's first cover the basics of digestion.

How does food get digested?

Inside your body is a 30 ft (~9.14 m) long, winding tube that extracts nutrients and water from the food you eat. This is your digestive system.

Here's a basic overview of the digestion process. (Note: I'm only covering the organs shown in the above diagram, as they relate most to the explanation of your rumbling tummy. Other organs, like the liver, pancreas, gallbladder, etc., are also involved in the complex process of digestion.)

1. Chewing and swallowing: First, each bite of food gets chewed in your mouth with saliva and then travels down your esophagus into the stomach.
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2. Stomach churning: Once in your stomach, the food gets broken down further with the help of acid, enzymes, and a churning motion.
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3. Small intestine nutrient absorption: The food is passed to your small intestine, which uses more enzymes to absorb nutrients into your body.
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4. Large intestine water absorption and release: The waste product goes to your large intestine/colon, which absorbs water until it finally exits through your rectum.

One critical component of your digestive system is the movement of food, sometimes going up against gravity. A series of contractions known as peristalsis is responsible for passing the food baton from your esophagus all the way to your rectum.

Peristalsis is essentially a wave-like motion that moves churned-up food, which contains solids, liquids, and gases. Your stomach also uses peristalsis to break down food and mix it with the acids and enzymes, contracting muscles about every 20 seconds.

These muscle contractions are the reason you occasionally hear a rumbling sound from your tummy. All of this squeezing and squishing of partially digested food echoes through the hollow tube of your digestive tract, amplifying the rumbling sounds.

In short, the sounds from your rumbling stomach (and intestines) are the acoustics of a working digestion system.

Does stomach growling mean you're hungry?

The sounds you hear from your stomach and intestines can happen both when you're digesting food and when you're hungry. Having food in your system can muffle the sounds, which may be why we mainly notice them when we're hungry.

When your stomach is empty, your brain releases ghrelin, known as the "hunger hormone," to stimulate your appetite. This hormone also signals your digestive muscles to prepare by restarting the muscle contractions of peristalsis. Why? These contractions sweep up any lingering food, and the rumbling sounds and vibrations cue you feel hungry.

How do you prevent stomach growling?

Stomach growling is perfectly normal, but if your tummy tunes are bothering you, here are a few tips to reduce them:

1. Eat many small meals instead of a few large ones. This eating schedule will more often mute your sounds since there's food in your system.
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2. Drink more water. Water will also help muffle the sound of your stomach growling while supporting your digestive system.
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3. Eat more slowly. Chewing your food properly will reduce the amount of air that you swallow into your digestive system.
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4. Eat fewer foods that cause gas. Things like carbonated drinks, dairy products, cruciferous vegetables, beans and lentils, and sugar substitutes can lead to excessive gas.
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5. Reduce stress. When you're feeling stressed or scared, your gut responds, like how you feel butterflies in your stomach when you are talking your crush. This makes it more likely for your stomach and intestines to create noises.

--- Thanks for reading this week's newsletter! If you have any thoughts, questions, or favorite GIFs, my inbox is always open. Just hit reply to send me a note! :) ​ All my best, Caitlin ​Click here to read five facts about Caitlin​

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​Sources for this week's newsletter​

🌐 Wikipedia article of the week

​Nut rage incident​

"The nut rage incident, colloquially referred to as "nutgate"... was an air rage incident that occurred on December 5, 2014, at John F. Kennedy International Airport in New York City onboard Korean Air Flight 086. Heather Cho (Korean name: Cho Hyun-ah; later changed to Cho Seung-yeon), Korean Air vice president and daughter of Korean Air CEO Cho Yang-ho, dissatisfied with the way a flight attendant served nuts on the plane, ordered the aircraft to return to the gate before takeoff."

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👀 Catch up on other curious questions

• ​Why do we eat cake on birthdays?​​
• ​Why are there more decimals between 0-1 than whole numbers between 0-∞?​​
• ​What makes you feel full when you're eating?​​

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