What is the vagus nerve – and how it connects your gut and brain

It’s the chemical communication along the gut-brain axis that explains why you might feel ‘sick with worry’ or experience ‘butterflies’ when you’re excited. Sometimes, miscommunication can occur along the vagus nerve – the wrong signals are sent, or the right ones are misinterpreted. For people with irritable bowel syndrome (IBS), this can trigger gut symptoms such as diarrhea, constipation, or abdominal pain.

While anxiety and stress can contribute to these disrupted signals, there are effective ways to retrain how your gut and brain communicate through the vagus nerve. Identifying your triggers and practicing mind-calming techniques can help regulate gut responses, ease IBS symptoms, improve emotional wellbeing, and break the ongoing gut-anxiety cycle.

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The gut-brain connection: how your nervous system influences IBS

Research shows that IBS is more than just a gastrointestinal disorder – it’s a complex gut-brain condition involving constant two-way communication between your digestive system and your brain. Understanding this connection is key to managing symptoms effectively.

To understand the vagus nerve and its crucial role in symptom control, it helps to first explore your autonomic nervous system (ANS) – the network that controls automatic body functions such as digestion, breathing, and heart rate.

Within the autonomic nervous system are three main sub-systems that work together to regulate how your body responds to stress, food, and emotion:

1. The enteric nervous system (ENS) – the network of neurons that controls digestion and gut movement.
2. The sympathetic nervous system – activates your body’s “fight or flight” stress response.
3. The parasympathetic nervous system – supports “rest and digest” functions that help calm the body.

Let’s start with the enteric nervous system Most people who don’t have IBS rarely think about their gut beyond its role in breaking down food and absorbing nutrients. But your ENS is far more sophisticated – it contains around 500 million neurons and independently manages nearly every aspect of digestive function. That’s why it’s often called your “second brain.”

The ENS communicates messages continuously with your central nervous system (CNS) – your body’s main processing center – through what’s known as the gut-brain axis. This two-way communication happens primarily through the vagus nerve, a long, intricate network that transmits messages between your gut and brain.

In addition to nerve signaling, your ENS and CNS also communicate through hormone secretion, gut bacteria (the microbiome), and the HPA axis, which regulates your body’s stress response. When these systems are balanced, digestion runs smoothly. But when communication is disrupted – due to stress, inflammation, or nervous system dysregulation – symptoms such as bloating, pain, and altered bowel habits can appear or worsen.

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Understanding your fight or flight response and its impact on IBS

Your sympathetic and parasympathetic nervous systems work together to regulate how your body responds to stress – and both can have a major influence on IBS symptoms.

When you’re under pressure and feeling stressed, your brain activates the sympathetic nervous system, triggering what’s known as the fight or flight response. Messages travel along the HPA axis (hypothalamic–pituitary–adrenal axis) to your gut, signaling your body to release adrenaline and conserve energy by slowing digestion. Instead of breaking down food efficiently, your body prepares to deal with a perceived threat. Depending on your body’s sensitivity, this can lead to either:

• Slowed digestion, causing constipation and bloating, or
• Accelerated digestion, resulting in diarrhea or cramping

When the stress passes and your body feels safe again, the parasympathetic nervous system – controlled largely by the vagus nerve – takes over. This activates your body’s natural “rest and digest” mode, slowing your heart rate, relaxing your muscles, and re-engaging healthy digestion.

While the sympathetic system is essential for survival during real danger, it can also be triggered by everyday stressors – things like worrying about eating certain foods, anticipating a flare-ups, or feeling anxious when away from home.

For people with IBS, this chronic low-level stress can cause the sympathetic system to stay switched on too long, sending repeated “danger” signals through the vagus nerve. The result is disrupted digestion and heightened gut sensitivity.

These stress-related gut reactions are extremely common, and research shows that generalized anxiety disorder (GAD) is up to five times more common in people with IBS. Over time, this persistent stress response can increase visceral hypersensitivity – meaning your intestines become more reactive to normal sensations – which contributes to pain, discomfort, and ongoing symptom flare-ups.

Learning to regulate your stress response and support vagus nerve function can help restore balance between the sympathetic and parasympathetic systems, improving both emotional wellbeing and digestive comfort.
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When gut-brain signals misfire: how vagus nerve communication affects IBS

The vagus nerve is responsible for carrying constant two-way messages between the gut and brain, coordinating digestion, stress response, and inflammation. When these gut-brain signals misfire, communication breaks down along what’s known as the gut-brain axis – and that’s when IBS symptoms often begin to appear.

For some people, a vagus nerve misfire  might cause mild nausea before a stressful event, such as public speaking or travel. For others, this disrupted communication happens daily, leading to ongoing abdominal discomfort, constipation, or diarrhea.

In IBS, these miscommunications can occur in two ways: the vagus nerve might send the wrong messages, or the brain may misinterpret normal gut signals as a threat. Either pattern can disrupt digestion and trigger symptom flare-ups, especially during times of stress or anxiety.

When vagus nerve communication works properly, messages between the brain and gut stay clear and balanced, keeping digestion steady and symptoms minimal. But when the system becomes overstimulated or confused, even ordinary digestive processes can feel painful or unpredictable. Strengthening vagal tone and calming the stress response can help restore this balance, reducing both symptom sensitivity and frequency over time.

Gut-directed hypnotherapy and your vagus nerve

Many people with IBS find themselves stuck in a repeating cycle: anxiety triggers gut symptoms, and those symptoms trigger more anxiety. This ongoing gut–mind feedback loop can keep the nervous system in a heightened state of stress. One effective way to help interrupt that loop is through gut-directed hypnotherapy.

Gut-directed hypnotherapy works by calming the mind while gently activating the parasympathetic nervous system through the vagus nerve. Programs like Nerva use structured audio sessions designed to promote deep relaxation, retrain gut–brain communication, and reduce sensitivity along the digestive tract.

When the vagus nerve is stimulated through relaxation and focused breathing, it can help release acetylcholine, a neurotransmitter that lowers heart rate, ease and calm your stress response , and supports healthy digestion. This vagal activation helps shift the body out of “fight or flight” mode and back into a “rest and digest” state, giving both the mind and gut time to recover.

Regular gut-directed hypnotherapy sessions not only reduce gut sensitivity and symptom frequency but can also improve sleep quality, lower baseline anxiety, and enhance overall wellbeing. Over time, this approach helps restore a balanced relationship between the brain and gut, reducing flare-ups and improving resilience against everyday stressors.

Breathe your way to calm: how diaphragmatic breathing supports gut health

Diaphragmatic breathing is a simple yet powerful way to interrupt the stress–symptom cycle and activate your parasympathetic nervous system through the vagus nerve.

Also known as belly breathing, this technique  fully engages your diaphragm – the large muscle at the base of your lungs — along with your stomach and abdominal muscles, allowing you to take deeper, slower breaths. Most people naturally fall into shallow chest breathing, which keeps the body in a low-level state of stress. In contrast, diaphragmatic breathing increases oxygen flow, slows your heart rate, stabilizes blood pressure, and helps calm the nervous system.

By stimulating the vagus nerve, diaphragmatic breathing promotes relaxation throughout the body and supports digestion. Research shows that regular practice can also enhance gut motility — the speed and coordination of movement through the intestines – which helps reduce bloating, discomfort, and irregular bowel habits.

Even a few minutes of intentional breathing each day can help restore balance to your gut–brain connection, reduce stress-related symptoms, and build resilience against future flare-ups.

Diaphragmatic breathing in four steps:

‍Step 1: Lie down comfortably with your legs straightened out in front of you.

‍Step 2: Place one hand on the chest and the other hand on your abdomen above your navel.

‍Step 3: Inhale through your nose, hold for a moment, and then exhale through your mouth. Your mouth should be open for the exhalation (some people like to purse their lips very slightly to feel the air leave their chest and mouth). The aim is for your abdomen to rise while your chest and shoulders stay still. Imagine a balloon is inflating and deflating inside your abdomen. This should be done slowly. Count to five with each inhalation/hold/exhalation.

‍Step 4: Practice 30 breaths at a time (for about five minutes) every day when you notice symptoms. Once you feel competent, you can try doing the exercise sitting and/or standing.

Your goal? Maintain your breathing at this rate for 15 minutes every day. 

Developing this habit makes it physiologically impossible for your SNS to be in total control. 

If you choose to try gut-directed hypnotherapy, you can apply this breathing technique during your daily sessions to ensure the therapeutic suggestions are being absorbed in a relaxed state, teaching your body to be calm and embrace healthy changes.

The cognitive defusion circuit-breaker: retraining your mind–gut response

Practicing cognitive defusion is a powerful way to interrupt the IBS-anxiety loop, support vagus nerve regulation, and activate the parasympathetic nervous system.

Start by noticing how you think about IBS. Many people tend to treat distressing thoughts as facts – for example, “I’m going to be in pain forever” or “I just know I’ll have diarrhea after dinner.” These thought loops keep the body in a heightened state of stress, keeping the sympathetic nervous system on alert and disrupting digestion.

Cognitive defusion teaches you to recognize these thoughts for what they are – passing mental events, not absolute truths. In practice, it means learning to look at your thoughts rather than from them, allowing you to observe them without becoming emotionally entangled.

A simple place to begin is by changing your internal language. Compare the difference between “My IBS is never going away” and “I’m noticing anxiety about my IBS.” The second phrasing distances you from the emotion and lowers its intensity, helping your parasympathetic system regain control. Over time, this shift reduces symptom-related anxiety and allows your body to stay in a calmer, more regulated state.

Here are a few evidence-based cognitive defusion exercises to try:

• Sing your negative thoughts – putting distressing thoughts to a tune helps you hear them differently and detach from their emotional weight.
• Make it a movie – visualize a stressful thought about your symptoms appearing on a movie screen and slowly scrolling away, as if you’re watching it pass without reacting.
• Praise the brain – when an unhelpful thought appears, simply acknowledge it with “Thanks for that, brain.” This reinforces awareness that your mind is trying to help, even when it’s mistaken.

Regular cognitive defusion practice helps calm the stress response, reduces anxious rumination, and promotes vagus nerve activation – ultimately helping to regulate digestion and improve symptom control over time.

FAQs about the vagus nerve and IBS

How does the vagus nerve affect IBS?
The vagus nerve connects your brain and gut, helping regulate digestion, inflammation, and stress responses. When this communication becomes disrupted, it can trigger or worsen IBS symptoms such as bloating, pain, constipation, or diarrhea.

Can you improve vagus nerve function naturally?
Yes. Techniques that activate the parasympathetic nervous system — like gut-directed hypnotherapy, diaphragmatic breathing, meditation, and cognitive defusion — can strengthen vagal tone and support balanced digestion.

Why does stress make my IBS worse?
Stress activates the sympathetic nervous system (the “fight or flight” response), which suppresses digestion and increases gut sensitivity. When this stress response becomes chronic, IBS symptoms often flare.

Does gut-directed hypnotherapy really help?
Yes. Clinical studies show gut-directed hypnotherapy can reduce IBS symptoms by improving vagus nerve communication and calming the stress response. Programs like Nerva make this therapy accessible and easy to integrate into daily routines.

How long does it take to see results from vagus nerve exercises?
Most people notice improvements in symptoms, stress, or sleep after a few weeks of consistent practice. Regular engagement helps strengthen the gut-brain connection and promotes long-term symptom relief.

The wrap-up

The way your brain and gut communicate through the vagus nerve has a powerful influence on your IBS experience. When stress and anxiety disrupt this communication, symptoms can intensify. By learning to activate your parasympathetic nervous system and support healthy vagus nerve function through gut-directed hypnotherapy, diaphragmatic breathing, and cognitive defusion, you can ease stress, restore digestive balance, and improve overall wellbeing.

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