200 Million Reasons Your Stomach Hurts
The surprising connection between your breath, your brain, and your bowels
This is my 100th post of A Breath Well Taken. I’ve been stressing about it all week.
Every topic felt too small. Or too big. Or not quite right for the occasion. And if that doesn’t feel enough like Goldilocks for you, I started drafting this post multiple times and kept changing it.
I considered writing about the history of breathwork, or listing 100 things I’ve learned, or saying something exceedingly profound trite about the breath as a metaphor for life.
And then somewhere around draft four (maybe five?), I noticed what my body was doing while I was overthinking this.
My stomach was in knots.
And so it turns out that that is exactly what this post is about.
If you’ve been here for any part of the ride, thank you. Now let’s get into it.
Your Gut Has a Brain of Its Own
Your gut contains anywhere from 200-600 million nerve cells. Scientists call this the enteric nervous system. Some of them call it the second brain, and even though that’s not literal, it kind of is.
It’s a separate, complex neural network lining your entire digestive tract, from your esophagus to your rectum, capable of operating largely independently of the brain in your skull. (Let us take a moment to note that this 100th blog is also the first – and surely one of, if not the only – times I’ve ever written “rectum” in a post.)
Your two brains are in constant communication. Their primary channel is the vagus nerve, which is the longest cranial nerve in the body. It runs from your brainstem through your chest and into your abdomen.
What’s even more wild is that about 80% of the signals on that nerve travel upward, from gut to brain, not the other way around. Your digestive system is constantly sending your brain information – about your physical state, your environment, and even your emotional experience.
Gut feelings are not just poetry. They’re neuroscience.
Digestion is the First Thing to Go
When your nervous system shifts into sympathetic mode – the activated, alert state that high achievers spend a meaningful portion of their day in – digestion is physiologically deprioritized. Blood flow moves away from the digestive organs and toward the muscles and systems needed for immediate response. Motility slows. Digestive enzyme production drops. The gut goes into standby.
This is why, in the middle of an intense workout, you’ve probably never had to stop to use the restroom. Your body is very much focused on the work at hand.
And it’s also why stress shows up as bloating, cramping, acid reflux, constipation, or my personal favorite, that vague, low-grade digestive wrongness that’s hard to name. It’s not psychosomatic. It’s your body doing exactly what it’s designed to do… and what it’s designed to do under perceived threat is incompatible with digesting your lunch.
The problem is that most people spend a chunk of the day in a state the nervous system reads as active pressure. Even when the actual threat is just a full inbox and a looming deadline, digestion suffers accordingly, and for some, chronically.
Give Your Internal Organs a Massage
The diaphragm is the primary muscle for breathing. It sits directly above your stomach, liver, and intestines. When you breathe shallowly (the default under chronic stress), the diaphragm doesn’t move much. When you breathe slowly and deeply, it drops with each inhale and rises with each exhale, making direct physical contact with your digestive organs with every single breath.
This does two things at once. The mechanical movement of the diaphragm gently massages the stomach and intestines. And the slow, extended exhale that comes with deep diaphragmatic breathing stimulates the vagus nerve, shifting the nervous system from sympathetic to parasympathetic – that is, from fight-or-flight to rest-and-digest.
You are using your breath to bring your gut back online.
Sounds like a strong statement, but the research is there. A randomized controlled trial found that slow diaphragmatic breathing significantly improved both symptom severity and bowel function in people with IBS. Separate research showed that it reduces acid exposure in people with GERD. A 2025 study found that three minutes of breathing exercises three times a day, practiced over six weeks, meaningfully improved bloating symptoms.
The most practical time to apply this is before you eat.
Most of us start a meal already in “go” mode: still in the last meeting mentally, checking something while we chew, eating standing at the counter. But your digestive system needs a parasympathetic signal before it can do its job well. A few slow, deep breaths before you pick up your fork is not a wellness affectation. It is a physiological primer.
Before You Take a Bite
Sit down. Place one hand on your belly and one on your chest. Take a slow breath in through your nose; let your belly push into your hand first, then let the breath expand your ribcage outward. Your chest should stay relatively still. Exhale slowly through your nose, letting your belly flatten all the way. Completely exhale before the next breath begins.
Try it for two minutes, keeping the breath slow and full.
It’s not about trying to relax (though you probably will). It’s about giving your nervous system a signal it already knows how to respond to: that this is a safe moment, digestion is allowed, and the inbox will still be there in ten minutes.
Your second brain is paying attention. Give it something useful to work with.
Last Gasp
“To eat is a necessity, but to eat intelligently is an art.”
— François de La Rochefoucauld
P.S. If you enjoyed this article, there’s much more in my free weekly newsletter, The Full Exhale. Sign up and I’ll send you three breaths you can use to change your state on the go, no matter where you are or what you’re doing. Grab it here →