How does stress affect the digestive system?

Medically reviewed on November 22, 2022 by Amy Harris, MS, RN, CNM. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.

Table of contents

• The effect of your body’s stress response
• How to reduce your stress levels
• Understanding stress with Everlywell
• Related content

We likely all feel stress at various life stages, whether you’re waiting to hear if you got your dream job or anticipating a difficult family situation. So, can stress make you get sick? That depends on what kind of stress you are dealing with. There are two types of stress we can experience as humans: good stress and bad stress.

Good stress is characterized by feelings of excitement and is often felt in the short term. Bad stress, on the other hand, can persist for long periods of time and is typically accompanied by anxiety or poor concentration [1].

Unfortunately, chronic stress can impact the whole body and negatively impact your gut and digestive tract.

The effect of your body’s stress response

Our stress response is often referred to as “fight or flight.” It’s the body’s reaction to fear or a perceived threat and may trigger individuals to flee or combat physical danger. However, psychological or mental stress may also activate your body’s “fight or flight” response, which may develop from a difficult work meeting or looming deadline.

It’s complex and involves three stages [2]:

• It starts in the brain – When something stressful happens to you, the amygdala (a region of your brain) kicks into action. It tells your hypothalamus that there’s a problem and that it needs to make your body do something about it.
• Adrenal glands play a role – Once the hypothalamus gets this distress signal, it responds by telling your adrenal glands to start making adrenaline. This hormone spikes your heart rate, makes you breathe faster, and increases your blood pressure, helping your body prime itself in case you need to actively respond to the stressor.
• Cortisol is its second defense – If your brain continues to think the situation is threatening, the hypothalamus will start the process of telling your body to make cortisol. Cortisol is often known as the stress hormone and will keep your body elevated until your brain believes the danger has passed. Once the threat is gone, your cortisol levels will decrease.

So, how does stress affect the digestive system? When your body’s stress response is activated, digestion is suppressed, and if the stress persists, the digestive system may experience irritation or upset.

Stress can cause ulcers

If you’ve been experiencing persistent stomach pain, stress may be the culprit. More specifically, you may have a peptic ulcer—a lesion on the lining of your digestive tract, often found in the stomach or small intestine [3].

Our understanding of what causes ulcers has shifted since H. Pylori (a bacteria) has been discovered as a leading cause. However, according to one study, stress may affect your chances of developing ulcers [4]:

• The study aimed to determine whether people who self-reported experiencing high levels of stress would have a higher risk for peptic ulcers—meaning that they would either be diagnosed with ulcers during follow-ups or need triple treatment for a peptic ulcer.
• The analysis the researchers performed found evidence that those individuals at the highest stress level had a 2.2-fold increase in risk relating to peptic ulcers when compared to the lowest stress group.

While stress may not be the primary cause of peptic ulcers, the study does suggest that chronic stress may put individuals at an increased risk of stomach or intestinal ulcers.

Stress may lead to IBS

Irritable Bowel Syndrome (IBS) is a fairly common condition, although it’s not one that healthcare providers and researchers fully understand yet.

You may be suffering from IBS if you’re experiencing most or all of the following digestive symptoms:

• Cramping
• Bloating
• Stomach pain
• Mucus in your stool
• Gas (beyond a normal amount)
• Constipation, loose stool, or a combination of the two

That said, research indicates that stress may trigger irritable bowel syndrome in three ways [5]:

• Stress may affect the gut’s microbiome
• Stress may increase the intestine’s sensitivity
• Stress may activate the gut-brain axis

In turn, stress can upset the digestive system, triggering IBS or IBS flare-ups. Because IBS may be a stress-sensitive disorder, one study suggests that IBS management should focus on relieving feelings of unease and anxiety in patients’ day-to-day lives [5].

GERD may be linked to high stress

Gastroesophageal reflux disease (GERD) is an extreme type of acid reflux that occurs after stomach acid repeatedly flows to and from the mouth and stomach, which can irritate the esophagus and cause reflux esophagitis.

While GERD can be managed with medication or diet changes, managing stress levels may also help ease GERD-related symptoms. One Korean research study found that psychological stress may be correlated to GERD [6]:

• Out of those with reflux esophagitis, 13.2% reported high stress levels
• The higher the stress, the more likely GERD was to be serious
• Stress may also increase heartburn, one of the mains symptoms of GERD

While you can help alleviate your GERD symptoms with a treatment plan, managing stress levels may also help ease the physiological effects of GERD.

Stress can harm your gut microbiome

Your gut is full of trillions of tiny bacteria and microbes that work together to aid key bodily functions related to metabolism, digestion, and pathogen prevention, as well as immune function [7].

That said, your gut and brain are connected through the gut-brain axis—two-way signaling between the gastrointestinal tract and the central nervous system. As such, chronic stress may impact your flourishing gut flora and cause digestive issues.

One study suggests that stress may affect your gut bacteria through the following mechanisms [8]:

• Stress hormones – The adrenaline spikes from your body’s stress response can have a material impact on your gut. When adrenaline is released, it can encourage certain types of harmful bacteria to grow in amounts up to 10,000 fold and make that bacteria more infectious. This harmful bacteria can then overtake and crowd out the helpful natural flora of your gut.
• Inflammation – When you’re overly stressed, your brain sends distress signals to your gut, and these signals can cause inflammation. When your stomach becomes inflamed, pathogenic bacteria can bloom. These blooms can hurt your existing gut flora and cause your gut to become leaky.

That said, your gut flora is worth protecting, and cutting down on your stress is one way to help keep it happy and healthy.

How to reduce your stress levels

Reducing the amount of stress you feel day-to-day may help support both your gut health and full-body health. To relax your body and mind, Harvard Health Publishing suggests that the following psychotherapy treatments might be a smart place to start [9]:

• Relaxation therapy – Through visualization, deep breathing, and muscle relaxation exercises, relaxation therapy aims to help you experience stress less intensely and to stop yourself from becoming stressed in the first place.
• Cognitive behavioral therapy (CBT) – This form of therapy is geared toward those who experience regular anxiety. Patients unlearn thought patterns and replace them with helpful coping skills to mitigate feelings of stress.

If you’re experiencing high stress levels or gastrointestinal discomfort, speak with your healthcare provider to identify a management plan that works best for you and your body.

Understanding stress with Everlywell

If you're interested in learning more about your own specific stress response, Everlywell can help. The Sleep & Stress Test lets you collect your sample at home and mail to a laboratory for testing (prepaid shipping is included with the kit). The secure, online results (which you'll receive in just days) will provide you with information about your stress and sleep hormone levels (including cortisol and melatonin) and how well-balanced they are.

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References

1. Good stress, bad stress. Stanford Medicine News Center. Published December 21, 2012. Accessed November 4, 2022. URL
2. Understanding the stress response. Harvard Health. Published July 6, 2020. Accessed November 4, 2022. URL
3. Peptic ulcer disease. Penn Medicine. Accessed November 4, 2022. URL
4. Deding U, Ejlskov L, Grabas MPK, Nielsen BJ, Torp-Pedersen C, Bøggild H. Perceived stress as a risk factor for peptic ulcers: A register-based Cohort Study - BMC Gastroenterology. BioMed Central. Published November 28, 2016. Accessed November 4, 2022.
5. Qin H-Y, Cheng C-W, Tang X-D, Bian Z-X. Impact of psychological stress on irritable bowel syndrome. World Journal of Gastroenterology. Published October 21, 2014. Accessed November 4, 2022.
6. Song EM, Jung H-K, Jung JM. The association between reflux esophagitis and psychosocial stress - digestive diseases and Sciences. SpringerLink. Published September 22, 2012. Accessed November 4, 2022.
7. Sidhu M, van der Poorten D. The gut microbiome. Aust Fam Physician. 2017;46(4):206-211.
8. Madison A, Kiecolt-Glaser JK. Stress, depression, diet, and the gut microbiota: human–bacteria interactions at the core of psychoneuroimmunology and nutrition. ScienceDirect.
9. Stress and the sensitive gut. Harvard Health. Published August 21, 2019. Accessed November 4, 2022. URL