How Stress Leads to IBS

ibs nervous system wellness Mar 12, 2019

There is no doubt that the gut is sensitive to emotion. Many are familiar with “butterflies” in your stomach or loose stool with anxiety. Well, research reveals just how the gut-brain connection influences our emotional response.

It makes sense that the brain has direct influence over the gut. The brain is the master control, which sends signals to the digestive tract through our autonomic nervous system to enhance overall function and optimize nutrient breakdown and absorption. This includes the secretion of stomach acid, motility of the gut and blood flow to the digestive tract, controlled by the vagus nerve and glandular/hormonal output. [1]

During stress these signals get disrupted. The body diverts energy away from digestive function and increases adrenalin, which directs circulation towards the heart and muscles to “fight or flight”. Chronically, this wreaks havoc on your digestion. Many experience heartburn, bloating, gas, reduced appetite, constipation or diarrhea and overall poor digestion, many symptoms that mimic IBS.

In those with IBS, the gut-brain signals become disrupted. Those with diarrhea-predominant IBS are shown to have a heightened autonomic and stress response, also known as hyper-
responsiveness of the autonomic nervous system.[2] Interestingly, those with constipation-predominant IBS present with a significantly lower autonomic response of the vagus nerve.[3]

Stress, anxiety, depression and stressful life events are some of the most significant risk factors for the development of IBS.[4] Infection can lead to physical stress on the body, in fact, recent meta-analysis demonstrates a six fold increase in the risk of developing IBS after an intestinal infection, which remains elevated up to two to three years post infection.[5,6]

The Second Brain

As it turns out, the communication between the gut and the brain is a two way street. The gut, which is also called the second brain, influences the brain’s emotional response, including the release of stress hormones (cortisol and CRH). Research shows that those who suffer from digestive complaints are at a higher risk of mental health complaints, such as depression and anxiety.[7]

The Microbiome & Probiotics

To add another layer to the story, emerging data shows how the gut microbiome affects brain signalling. Changes within the gut bacteria are shown to influence pain perception in those with IBS by influencing inflammation, the stress response, immune function and areas in the brain that process emotions, called the amygdala. These bacteria are shown to produce a number of gut hormones, short chained fatty acids (SCFAs), and neurometabolites (GABA, norepinephrine, dopamine), which modulate the function of the nervous system and overall mood.[8,9]

Probiotics are now being used to alter psychological stress and improve pain sensitivity in those with IBS. These products have such a strong effect on the brain that some studies show the use of probiotics to improve mood significantly in those with mild to moderate depression.[10]

Next Steps: Testing

Don’t guess, assess! Find out through objective functional testing to see the underlying mechanism of your symptoms.

  • HRV (heart rate variability) shows the state of the nervous system to assess for heightened autonomic and stress response
  • CDSA stool testing revels the function of your digestive tract and microbial balance
  • Hydrogen breath test (SIBO) identifies an overgrowth of bacteria in the small intestine, found to be positive in up to 84% of those with IBS.

Based on these findings it is imperative that the relationship between the gut and the brain be addressed during treatment. For those who suffer from mental health disorders, improving gut
function while reducing autonomic stimulation (the stress response) can be an effective approach to modulate the nervous system to find relief from anxiety, insomnia and depression.

In addition, addressing gut concerns can optimize your digestion and absorption of neutraceuticals and foods, which contain essential nutrients to improve your recovery and repair.

On the other end of the spectrum, it is important to address the balance of the nervous system when digestive symptoms are present. Alterations in the autonomic nervous system can not only
affect functional gut disturbances, but hormone, immune, cardiovascular, detoxification and reproductive systems as well.[11]

Could stress be affecting your digestive complaints?

Physical signs of stress: [12]

  • Stiff or tense muscles, especially in the neck and shoulders
  • Headaches
  • Sleep problems
  • Shakiness or tremors
  • Recent loss of interest in sex
  • Weight loss or gain
  • Restlessness
  • Behavioral symptoms
  • Procrastination
  • Grinding teeth
  • Difficulty completing work assignments
  • Changes in the amount of alcohol or food you consume
  • Taking up smoking, or smoking more than usual
  • Increased desire to be with or withdraw from others
  • Rumination (frequent talking or brooding about stressful situations)

Emotional symptoms:

  • Crying
  • Overwhelming sense of tension or pressure
  • Trouble relaxing
  • Nervousness
  • Quick temper
  • Depression
  • Poor concentration
  • Trouble remembering things
  • Loss of sense of humour
  • Indecisiveness

Subscribe to our YouTube channel for stress coping strategies proven to improve cortisol levels and quality of life!

In best of health,
Dr. Robyn Murphy, ND

1. Matteoli, G., Gomez-Pinilla, P.J., Nemethova, A., Di Giovangiulio, M., Cailotto, C., van
Bree, S.H., Michel, K., Tracey, K.J., Schemann, M., Boesmans, W., et al. (2014). A
distinct vagal anti-inflammatory pathway modulates intestinal muscularis resident
macrophages independent of the spleen. Gut 63, 938–948.

2. Punyabati, O., Luikham, L.A., and Singh, M.A. Sympathetic Response in Symptom
Subgroups of Irritable Bowel Syndrome (IBS).
3. Aggarwal, A., Cutts, T.F., Abell, T.L., Cardoso, S., Familoni, B., Bremer, J., and Karas,
J. (1994). Predominant symptoms in irritable bowel syndrome correlate with specific
autonomic nervous system abnormalities. Gastroenterology 106, 945–950.
4. Moloney, R.D., Mahony, S.M., Dinan, T.G., and Cryan, J.F. (2015). Stress-Induced
Visceral Pain: Toward Animal Models of Irritable-Bowel Syndrome and Associated
Comorbidities. Front. Psychiatry 6.
5. Thabane, M., and Marshall, J.K. (2009). Post-infectious irritable bowel syndrome. World
J. Gastroenterol. WJG 15, 3591–3596.
6. Thabane, M., Kottachchi, D.T., and Marshall, J.K. (2007). Systematic review and meta-
analysis: the incidence and prognosis of post-infectious irritable bowel syndrome.
Aliment. Pharmacol. Ther. 26, 535–544.
7. Haug, T.T., Mykletun, A., and Dahl, A.A. (2002). Are Anxiety and Depression Related to
Gastrointestinal Symptoms in the General Population? Scand. J. Gastroenterol. 37,
8. Dockray, G.J. (2014). Gastrointestinal hormones and the dialogue between gut and brain:
Gut-brain signalling. J. Physiol. 592, 2927–2941.
9. Zhang, Y., Ning, G., Handelsman, Y., and Bloomgarden, Z.T. (2010). Gut hormones and
the brain*. J. Diabetes 2, 138–145.
10. Carabotti, M., Scirocco, A., Severi, C., and Severi, C. (2015). The gut-brain axis:
interactions between enteric microbiota, central and enteric nervous systems. Ann.
Gastroenterol. 28, 203.
11. Vighi, G., Marcucci, F., Sensi, L., Di Cara, G., and Frati, F. (2008). Allergy and the
gastrointestinal system. Clin. Exp. Immunol. 153, 3–6.
12. Harvard Publications, H.H. The gut-brain connection. Retrieved from brain-connection

Get Access to the Quick and Simple Guide To Help Support Bloating, IBS & SIBO

Feel better with IBS & SIBO. A simple guide to reduce bloating, improve gut motility and boost energy so you can start getting relief today.


50% Complete

You're Almost There!

Please provide a few details to get you set up for the most useful tips on how to keep your gut healthy!