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Stress

Why Does Stress Make My Stomach Hurt?

The surprising biological link between the gut and brain.

Key points

  • The brain and the gut are wired together biologically in ways that make people's stomachs hurt when they're stressed.
  • Stress can trigger reflux, a knot in the stomach, nausea, bloating, cramping, and the urgent need to go to the bathroom.
  • The best approach to tummy troubles that are exacerbated by stress is to learn to manage stress effectively.

Many people with tummy issues know all too well that when they are stressed out: Their tummy bothers them more. Some people feel nauseous or get horrible reflux and heartburn. Others feel terribly bloated and gassy. Some people burp a lot. People with irritable bowel syndrome (IBS) are more likely to experience abdominal pain, cramping, and even an urgent need to run to the bathroom when they’re anxious, angry, or stressed.

Why does this happen?

It turns out that the gut and the brain are wired together pretty tightly. That is, the enteric nervous system (that controls the stomach and the intestines) communicates back and forth with the central nervous system (the brain and the spine) all the time. So GI symptoms often get worse when we’re stressed. This does not mean that your symptoms are “all in your head." Stress has a direct effect on the way the entire GI system works for pretty straightforward biological reasons.

All vertebrate animals (including humans) have a nervous system that controls just about everything that happens in the body. It’s divided into several different systems or sets of nerve cells that all talk to each other, including the central nervous system, which includes the brain and the spine, and the peripheral nervous system, which is further divided into the autonomic and the enteric nervous systems. The autonomic nervous system is composed of the sympathetic (fight or flight) and the parasympathetic (rest and digest) systems.

When we feel stressed, the entire nervous system gears up to help us meet whatever challenge we are faced with. The brain secretes adrenalin and cortisol (major stress hormones) and tells the autonomic system to increase breathing, heart rate, blood pressure, and muscle tension. This means that the throat, stomach, and intestines may tighten or even spasm, leading to feeling a lump in your throat, “butterflies” or a tight knot in your stomach, the sensation of needing to throw up, and/or increased intestinal cramping and urgency that sends you running to the bathroom. The enteric nervous system responds to stress because it is wired to.

Believe it or not, this is a great system to have in place from an evolutionary perspective. It helped our ancestors survive saber-toothed tiger attacks, hunt down wooly mammoths, escape savannah fires, and manage all the other massive challenges they faced that required a huge output of physical energy to run or fight. Unfortunately, this system is not as useful in helping us manage the challenges and stressors of modern life. Rush hour traffic that makes you late, unpaid bills, unpleasant meetings, looming deadlines, arguments with loved ones—all of these are stressful, but none of them requires a huge output of physical effort to survive them.

Sadly, our nervous system is still reacting to every stressor we encounter as if it were a saber-toothed tiger. That means we get all juiced up (with adrenaline, cortisol, and a pounding heart and muscle tension) and then have nowhere to go with all that energy. That’s why stress can make us feel physically terrible, up to and including dramatically worsening GI symptoms.

What not to do

Sometimes well-intentioned doctors will tell you to "reduce stress." The problem with this advice is that it can lead to avoidance. The only way to truly avoid stress is to avoid life, and that’s not desirable or sustainable. You may have tried this—skipping trips or events, staying home when you don’t feel well, not socializing, passing up jobs or challenging work assignments.

If you’ve tried avoidance, you know it doesn’t work. It might be tempting, and it might make you feel better in the short run, but in the long run, it’s depressing and demoralizing, and it hasn’t made your GI symptoms any better or easier to live with. In fact, avoidance tends to make things worse in the long term. Some people are so afraid of not making it to the bathroom “in time” that they stop going places where a bathroom might be hard to get to or embarrassing to use. If left untreated, this can morph into full-blown agoraphobia—extreme fear and avoidance of places because you’re so worried about vomiting or having an accident. This kind of avoidance can make your life truly miserable.

What’s the solution?

Learn how to manage stress, and the impact it has on your body, more effectively. (There are a number of ways to do that, which I’ll detail in future posts.) Relaxation training (which turns stress off) and physical activity (which burns stress off) are great ways to reduce the biological impact of stress on the GI system.

Learning not to catastrophize (or overestimate the chances of something really terrible happening, or how terrible it would be if something bad did happen) is also important. Since your brain is the master controller of your whole body (including your digestive system) the good news is that by changing how you think about things and how you manage and control your body’s stress response system, you can get a lot of relief from GI symptoms.

References

Keefer, L., Palsson, O.S., & Pandolfino, J.E. (2018). Best practice update: incorporating psychogastroenterology into management of digestive disorders. Gastroenterology 154(5): 1249-1257.

Hunt, M. (2022). Reclaim Your Life from IBS: A Scientifically Proven CBT Plan for Relief Without Restrictive Diets. Routledge Taylor and Francis Group, New York and London.

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