Stressed out Stomach? | How Stress Can Negatively Impact Digestion & Ways to Improve It

Have you ever been so nervous about something that you feel “sick to your stomach?” Or you really stressed about a test and you just feel nauseas? The gut-brain connection is a very powerful thing and is why stress can often lead to digestive issues.

Maybe I shouldn’t be smiling while talking about stress related stomach issues, but it makes me happy to share solutions with you!!!

Maybe I shouldn’t be smiling while talking about stress related stomach issues, but it makes me happy to share solutions with you!!!

Before we begin our chat, I want to give a little disclaimer - I am not a gastroenterologist or a registered dietitian, so if you are experiencing severe gut issues I encourage you to please see a professional! The information I’m sharing today is based on research I’ve done both in school and on my own, plus personal experience from healing my own gut. I worked with a Registered Dietitian who specialized in hormonal and digestive issues. The issues I’m talking about today are simply when stress is affecting digestion (and simple lifestyle changes you can make to help it), not when there is another intestinal problem going on, like SIBO(small intestinal bacterial overgrowth), gut-motility issues, parasites, celiac, or food intolerances. It’s important to note that stress can trigger problems like SIBO or leaky guy! However, we’ll get into that later ;)

Before we dive into discussing the gut-brain connection, it’s helpful to explain stress and the nervous system:

What is stress & The Stress REsponse?

Stress is an experience in which the demands of a situation exceed one’s perceived ability to cope. During the stress response, your body is preparing for a potentially threatening situation. A number of physiological changes take place, including the firing of neurotransmitters like adrenaline and noradrenaline and the secretion of hormones such as cortisol. You might notice an increase in your heart rate, anxiousness, and feeling a “knot” in your stomach. The stress response was helpful to our ancestors as a means of survival (i.e., running from a bear) but it’s not as beneficial in our modern, everyday sorts of stressors.

The Nervous System

The nervous system is first divided into the somatic (voluntary) and autonomic (automatic) nervous systems. The somatic nervous system controls voluntary movements via skeletal muscles. In contrast, the autonomic nervous system controls unconscious activities like your heartbeat, breathing, and digestion. We’ll be talking about the autonomic nervous system today, aka the things you don’t consciously control. The autonomic nervous system is then divided into the parasympathetic and sympathetic nervous systems. I’m not going to get deep into the neurological pathways and all the neurotransmitters involved - that’s best for college anatomy and physiology class… however, if you understand the basics of each system, you can better understand what’s going on in your own body.

The Parasympathetic and Sympathetic Nervous Systems

The parasympathetic and sympathetic nervous systems have opposite effects in the body. The parasympathetic is responsible for maintaining energy balance and efficiency in the body under normal conditions. It’s also referred to as “rest and digest” mode. The sympathetic is responsible for mobilizing the body in periods of activity, and what is activated during the stress response. It’s also known as “fight or flight” mode. Optimally our body should maintain a balance between the two systems because both are necessary.

When one system takes too much control, the body can start to express symptoms telling you something is “off.” Most people experience the effects of too much stress, or the sympathetic nervous system being in constant control, not letting their body get into the “rest and digest” mode of the parasympathetic nervous system. When we talk about the effects of stress on the body, we’re talking about this imbalance of the two systems. If we can tap into the parasympathetic nervous system, we can alleviate many of the symptoms caused by stress.

The Gut-Brain Axis

Signals from the brain to the gut play a critical role in maintaining optimal digestive function, reflex regulation of the GI tract, and modulation of mood states. The gut is often referred to as the second brain for a reason.

One of the well-known hormones that affect our mood, serotonin, is produced in the gut. Changes in stress levels can raise cortisol (the stress hormone) which can deplete serotonin. Serotonin has been shown to have an impact on digestion, not only mood. An increase in cortisol can be due to the fight or flight response, where the sympathetic nervous system takes over, as stated earlier. Digestion happens in the rest and digest mode, or when the parasympathetic nervous system is more in control. When the fight or flight mode takes over, the brain signals to the gut, “nope, we’re in danger right now - we can’t be digesting food!” Put simply, proper digestion cannot take place when the body is in a stressed out state.

sourced from:

sourced from:

Upon doing some more research on the gut-brain axis and serotonin, I came across an article with information from Dr. Michael Gershon, Professor and Chairman, Department of Anatomy and Cell Biology at Columbia University. “I first proposed that serotonin was an enteric neurotransmitter in the 1960s,” explains Dr. Gershon, “and by the early 1980s, my suggestion had been confirmed, and teams of scientists determined that serotonin was not only a neurotransmitter but also a signaling molecule that ultimately triggers peristaltic and secretory reflexes. Today, the gut is known to have at least seven different serotonin receptors.”

Stress does not only have hormonal effects; it can also cause changes to our gut microbiome. We have millions of bacteria in our gut which are vital to our health. They help our immune system by fighting off infection and help in the digestive process. Having a healthy and diverse gut bacteria is essential to our health. When the bacteria get out of balance, however, we can start to experience unpleasant symptoms such as bloating and indigestion. There should be more bacteria in the large intestine than the small intestine. Because stress can cause dysfunction in gut motility, the bacteria in our gut are not passing through to our large intestine properly. When bacteria are not effectively swept from the small intestine into the colon (large intestine) they begin to overgrow in the small intestine. This dysfunction is one of the ways SIBO can develop.

In addition to the stress impacting hormones and the gut microbiome, the way we think about food can impact how we’re digesting it. If you sit down to eat a burger and you’re just thinking “oh my gosh this is going to hurt my stomach, I’m not used to this!” you’re probably not going to digest it well. Likewise, if you’re thinking about how “fattening” a food is, your probably not going to digest it well either, which will likely trigger even more negative thoughts. Those negative thoughts about the food trigger the stress response and therefore impact digestion. Quite often people will cut out dairy or gluten because they hear it’s bad for them, and they convince themselves that those foods bother their stomach. Of course, some people do have real intolerances to those foods, but some people manifest them through their thoughts!

digestive Symptoms Caused by Stress

By now you’re probably thinking “just tell me how to fix my stomach!” We’re getting there! You might also be wondering how to decipher whether your gut issues are due to stress, or something more complicated.

Here are some symptoms that could be due to stress:

  • Changes to appetite

  • Frequent bloating after eating

  • Tightness, cramping, or knots in the stomach

  • Constant gas

  • Nausea or queasiness

  • Acid reflux or hear burn

  • Getting full unusually fast when eating

  • Feeling anxious or nervous around meal times

Ways to Decrease Stress and Improve Digestion

The biggest thing we can do to improve our stressed out stomach is to DECREASE STRESS. But how do we do that? A stressed out gut can be due to acute stress around eating times and due to chronic stress that builds up in our lives.

Decreasing stress around meal times

  • Practice more mindful & slower eating- Slow down and savor each bite of food! Properly chewing your food also helps activate adequate enzymes in the mouth to break down our food!

  • Deep breathing - Taking a few, mindful deep breaths before a meal can help activate the vagus nerve, stimulating the parasympathetic nervous system.

  • Minimize distractions! As much as we don’t like to admit it… our PHONES are a huge trigger of stress. Scrolling on Instagram or watching a show while eating distracts us from our meal and impairs digestion.

  • Sit down to eat! - A lot of us are on the go nowadays, and it’s tempting to just grab a granola bar and eat in the car on the way to work/school or hit up drive through on the way home. I encourage you to sit down and eat a full meal as often as you can. We all have busy days, but being more intentional with our meals can decrease stress around eating.

Decreasing overall stress levels

  • Practice deep breathing in between meals - This can help with the digestion process and prepare your body for the next meal. Often we eat the next meal without full digesting the previous one.

  • Yoga - I cannot praise yoga enough for how much it helped me heal my gut. Yoga focuses your mind on the breath (stimulating that parasympathetic nervous system!), and particular stretches can help move things along in the gut. I recommend more restorative, slow forms of yoga for improving your digestion over fast flowing classes/hot yoga.

  • Practice gratitude - This may seem weird, but recognizing what you’re grateful for has been shown to improve feelings of happiness and decrease stress. I like to write down my gratitude in the morning before breakfast (but anytime can be beneficial). Not only does this give my digestive system some time to “wake up” before I eat but, it also puts me in a state of gratitude before eating.

The Takeaways

If you’re experiencing mild to medium digestive issues, there’s a good chance it’s due to stress. Stress is one of the most detrimental things to our health, but often gets overlooked when trying to treat symptoms. Stress can be the root cause of many digestive issues. Instead of taking anti-acids or relying on digestive enzymes at every meal, you can start to get to the root of the problem by examining your stress levels.

I hope this blog post was informative and helped you understand how stress could be impacting your digestion, and hopefully got took away some helpful strategies to implement. We can never completely irradiate stress from our lives, but we can learn to better cope with stress, and in turn, experience better health!


Stress and the Gut: Pathophysiology, Clinical Consequences, Diagnostic Approach, and Treatment Options

How Stress Affects Digestion

IBS and Serotonin | Canadian Society of Intestinal Research