Is Stress Making You Bloated? Here's The Proof, and The Fix.

Have you ever felt bloated after a stressful day, even though you ate “clean”? You’re not imagining it - the brain and gut constantly communicate through a bidirectional network called the gut-brain axis. When your mind is overwhelmed, your digestion slows down, swells up, or spirals out.

The result? Bloating that has nothing to do with diet.

Stress really does hit the gut in a handful of ways, and it’s not just “in your head.” When cortisol spikes, your body essentially prioritizes survival mode over rest-and-digest mode. Here’s a more detailed breakdown the 5 most common things that happen in adults:

Your stomach and intestines are lined with layers of smooth muscle that rhythmically contract to push food along. Stress signals from the brain (via the vagus nerve and sympathetic nervous system) cause those muscles to tense up instead of moving in that steady wave-like motion.

• Result: Food lingers in the stomach or intestines, which can lead to gas buildup, cramping, or constipation.

• Extra detail: Some people experience the opposite — the muscles spasm and push food through too quickly, which can trigger diarrhea. Both extremes are the gut’s way of showing it’s “off balance” due to stress.

The stomach relies on hydrochloric acid (HCl) to break down proteins and trigger digestive enzymes. Stress throws this off in two possible ways:

• Too much acid: The stomach lining gets irritated, leading to burning sensations (heartburn, acid reflux).

• Too little acid: Food isn’t fully broken down, which means larger, undigested particles pass into the small intestine. These particles ferment more easily and create gas, bloating, and sometimes even nutrient malabsorption.

• Extra detail: Stress can also change the production of mucus that protects the stomach lining, making it more vulnerable to irritation.

Stress often changes how we eat without us noticing.

• Fast eating: Less chewing means food enters the stomach in bigger chunks, which is harder to digest.

• Mouth breathing or gulping: Stress can make you breathe faster and shallower, which leads to swallowing more air.

• Eating while distracted: If your brain isn’t focused on eating, it won’t send strong “digest” signals to the gut. This is why mindful eating — chewing slowly, pausing between bites — often reduces bloating.

• Extra detail: Swallowed air (aerophagia) doesn’t just leave as burps — a lot of it passes into the intestines, where it causes pressure and bloating.

The gut microbiome is like an ecosystem, with “good” bacteria helping with digestion, vitamin production, and keeping harmful microbes in check. Stress hormones like cortisol and adrenaline alter the gut environment in ways that bacteria feel directly.

• Shift in balance: Beneficial bacteria (like Lactobacillus and Bifidobacterium) may decline, while more inflammatory species increase.

• Result: Reduced resilience of the gut, more sensitivity to certain foods, and sometimes even increased inflammation.

• Extra detail: Stress can also reduce blood flow and mucus production in the intestines, making it harder for good bacteria to thrive.

“Gastric emptying” is how quickly food moves from your stomach into the small intestine. Cortisol and adrenaline divert blood flow away from the gut and toward muscles, preparing you to “fight or flee.”

• Effect: Digestion slows dramatically, and food can stay in the stomach for hours longer than normal.

• Result: Fullness, nausea, burping, and discomfort.

• Extra detail: For some, stress triggers the opposite (rapid emptying), which can cause loose stools or urgency. That’s why stress-related gut issues look different from person to person.

1. Slow Down at Mealtimes - Eat without distractions. Put the phone away. Chew slowly. Take deep breaths. This sends a signal to your body: it’s time to digest, not panic.
2. Try a Breathing Exercise - Before your first bite, take 3 deep breaths. Inhale for 4 counts, hold for 7, exhale for 8. Repeat.
3. Move Gently After Meals - Walk for 10 minutes or do some light exercise. Movement helps release trapped gas and stimulates digestion.

Here are some tips so you can actually apply these changes in your day-to-day life:

• At your next meal, sit down and eat without multitasking. No scrolling. No checking emails. Just you and your meal.
• Set an intention for your meal. It slows down your nervous system and kickstarts your digestion.
• After your next meal, take a walk around the block or put on a 5-minute stretching video.

Claisen’s custom bloat kits include science-backed solutions to support your lifestyle from both sides of the gut-brain axis:

• Magnesium glycinate - reduces cortisol levels and relaxes gut walls
• Probiotics - restores healthy bacteria impacted by stress
• Melatonin - improves sleep quality and regulates gut motility
• DGL (Deglycyrrhizinated Licorice) - helps soothe stress-related inflammation in the GI tract

When your mind calms down, your stomach follows. Get started today by taking our quick, 3 minute quiz to figure out what exactly the problem is, and how you can take advantage of Claisen to get better ASAP.

This article and its contents have been medically reviewed by Aditya Jain (MD at Harvard Medical School and Op-Ed Fellow at Doximity).

This article and its contents have been medically reviewed by Aditya Jain (MD at Harvard Medical School and Op-Ed Fellow at Doximity).