Somewhere between washing your hands 25 times a day, panicking about job stability, stressing over the state of the country, co-working with your significant other from the kitchen table, and not sleeping, you start to feel it. Not simply overwhelmed, but physically off—crampy, bloated, gassy, and…well, let’s just say your new form of cardio is sprinting to the bathroom. Could stress be what’s causing your diarrhea and digestive issues?
There’s no denying it: Stress can royally mess with your digestion. Numerous studies have linked psychological stress—whether from too much work, lack of work, losing a loved one, or managing your kids Zoom class schedule—to a range of digestive symptoms, which, left unmanaged can lead to more complications. And, per a recent Gallup poll, more than 60 percent of Americans say they experience significant stress on a daily basis, so that’s a whole lot of potential GI discomfort.
But why does stress have this effect, and what are the short and long-term implications? Here, we dive into the science and what you can do about it.
What effect does stress have on your body (and your GI tract)?
“A lot of people think digestion is just about gut function, when in reality it involves the nervous system quite a bit,” says Samantha Franceshini, a health coach with clinical expertise in gastrointestinal health at Parsley Health New York. In fact, your brain communicates back and forth, nonstop, with your enteric nervous system—a component of the autonomic nervous system embedded in the lining of the GI tract that regulates digestion—via the gut-brain axis.
So how does this all come into play when you’re feeling frazzled? Being stressed activates another part of the autonomic nervous system called the sympathetic nervous system, and triggers that famous “fight or flight” response—which, back in the day was meant to help you flee from dangerous animals. Unfortunately, today, even non life-threatening stressors like your 60-hour work week drives this response.
“Today, people are almost always on the go or distracted, and never sitting down to eat their meals—so we’re often in that fight or flight state when we’re digesting,” says Franceshini. “Think of it like trying to eat a meal while you’re running from a lion.”
When you enter a sympathetic-dominant state, your body releases hormones such as noradrenaline, adrenaline, cortisol, and corticotropin-releasing factor (CRF), explains Franceshini. These hormones, in turn, trigger a cascade of events in the body that prepare you for swift action. But they also essentially tell the enteric nervous system to down-regulate digestion. Here are a few things that happen:
- Contraction of GI sphincter muscles is altered, which can inhibit smooth muscle movement and slow food transit in certain portions of the GI tract (stomach and small intestines), while speeding up food transit in other areas (the lower bowel/colon).
- Blood vessels in the gut contract, diverting blood flow (and thus energy) away from the digestive system and to the limbs.
- Stomach acid and digestive enzyme secretions nearly grind to a halt, impairing your ability to properly break down food.
The counterpart to the sympathetic nervous system is the parasympathetic nervous system, known as the “rest and digest” system—and taking conscious steps to activate this system could be the key to solving your digestive woes. (More on that below!)
So, what are some specific ways stress can mess with your digestion?
Short-term effects of stress on digestion
Stress can pretty much start wreaking havoc on your health immediately. According to Franceshini, here are a few digestive issues you might experience.
- Reduced stomach acid + digestive enzymes. When you thoroughly chew your food, digestive enzymes are released in the mouth that prime your body for digestion and trigger the release of even more digestive enzymes and stomach acid, says Franceshini. But when you’re stressed and scarf down your food in two bites, you’re not producing nearly as much of these key digestive factors as you should.
- Reduced nutrient absorption. Because you’re not producing enough stomach acid and digestive enzymes, you’re not able to break down food enough to optimally absorb nutrients. For example, “stomach acid helps separate protein from minerals,” says Franceshini, “so if we don’t have good stomach acid levels, we can’t absorb things like iron and magnesium.”
- Constipation. Significant stress can cause diarrhea or constipation or diarrhea, and it’s not always clear what camp you’ll fall into until you experience it. As previously mentioned, stress hormones can affect how GI sphincters contract. This can slow the movement of food through certain areas of the GI tract such as the stomach and small intestines, which may contribute to constipation in some people. According to a review of research in the journal Medicine, people were more likely to have chronic constipation if they’d experienced stressful life events.
- Diarrhea. On the flip side, because stress hormones can speed up the movement of food through other portions of the GI tract such as the lower bowel or colon, stress can cause diarrhea in certain people. You might even alternate between the two if you’re exceptionally unlucky.
- Bloating + cramps. The slowed digestion caused by stress can also cause uncomfortable bloating. And, per the American Psychological Association, stress can cause muscle spasms in the bowel which can lead to painful cramping.
- Heartburn. It’s not uncommon for stress to trigger uncomfortable indigestion and heartburn, and that may be partially due to stress’s effect on lowering stomach acid. That might sound odd, but heartburn is a documented symptom of achlorhydria, a condition in which people don’t produce enough stomach acid.
Long-term effects of stress on digestion
In addition to the digestive symptoms above, here’s how constantly being on edge over the long term can negatively affect your gut and digestion.
- Irritable bowel syndrome (IBS): Research has solidified a relationship between stress and IBS, a condition characterized by recurring cramping, abdominal pain, bloating, gas, and diarrhea or constipation. According to a study in Research in Nursing & Health, psychological distress was associated with more severe bloating among women with IBS. While it’s not clear if chronic stress can cause IBS, it can make digestive symptoms worse.
- Nutrient deficiencies: Given that stress impairs your ability to break down food and optimally absorb nutrients, over time, this can lead to nutrient deficiencies, says Franceshini. Left unaddressed, nutrient deficiencies may lead to a range of health issues, including even more stress (particularly if you’re low in magnesium), or hormonal imbalances. Low iron, for instance, could interfere with production of thyroid hormones.
- Gut dysbiosis: A 2019 animal study in the Journal of Pediatric Gastroenterology & Nutrition found that social stressors led to less diverse bacterial communities in the intestine and a higher number of potentially harmful bacteria—an imbalance known as gut dysbiosis, which may play a role in conditions from IBS and irritable bowel disease (IBD) to cancer and diabetes.
- Increased intestinal permeability: Stress has also been associated with increased intestinal permeability (a.k.a. leaky gut)—meaning microbes and undigested food particles are able to essentially “leak” out of your intestines and into the bloodstream. Researchers believe this may trigger the chronic diarrhea that can occur with diarrhea-predominant IBS, along with a range of other issues, including widespread inflammation and food sensitivities.
Tips to soothe stress-related digestive issues
Combating these unpleasant side effects of stress comes down making a conscious effort to slooooow down. This will help activate your parasympathetic nervous system. “When the parasympathetic system is in a dominant state, the body is conserving energy, it’s slowing your heart rate, it’s increasing digestive secretions and enzymes, and it’s relaxing the sphincter muscles in your digestive system,” says Franceshini.
Here are some things Franceshini uses with her members at Parsley Health to engage the “rest and digest” system address the root cause of your stress and support your body’s digestive processes:
- Take a deep, cleansing breath before you eat. Taking a deep, deliberate breath before you eat can stimulate the vagus nerve, which can help directly upregulate the parasympathetic nervous system.
- Really chew your food. “Chewing is really the only voluntary thing we can do to control digestion,” says Franceshini. So you need to make it count. The process of slowly chewing triggers the release of enzymes and primes your whole body for digestion.
- When you eat, just eat. “A lot of the times when people are having digestive issues, they will see more benefits from just working on mindful eating and supporting upstream processes rather than going on an elimination diet,” says Franceshini.
- Sip chamomile tea 15-20 minutes before your meal. In addition to just being a nice calming ritual, chamomile is a digestive relaxant and known for triggering the parasympathetic state.
- Diffuse an essential oil at mealtime. Both lavender and bergamot have calming properties that can help activate the parasympathetic nervous system.
- Consider a magnesium glycinate supplement. Magnesium is a nervous system relaxer, which some Parsley Health docs have dubbed “nature’s anti-anxiety drug.” It also tends to get depleted during times of stress, so supplementing or loading up on magnesium-rich foods like almonds and pumpkin seeds is smart.
- Incorporate any stress-busting activity. Yoga, meditation, journaling—whatever gets you out of your frazzled heat and into the moment can trigger a parasympathetic state.
- Eat a nutrient-dense diet. A diverse, colorful, plant-heavy diet that also features probiotic-rich fermented foods is a great way to boost digestion and curb stress simultaneously. These 11 foods are proven stress busters.
Seeking treatment for digestive issues
If you’re experiencing ongoing or recurring digestive issues, it’s a good idea to get a professional medical opinion, whether you suspect they’re a result of stress or something else. Because the digestive symptoms above could be caused by any number of reasons, you’ll want to rule out infections, parasites, or other conditions that might be contributing as well.
A functional medicine doctor, such as those as Parsley Health, can run gut microbiome testing and work with you to address the root cause of your digestive troubles—whether that’s stress, nutrient deficiencies, an infection, or all of the above—not just the symptoms.