The Psychology Behind Irritable Bowel Syndrome


This post is written by a friend and colleague, Jessica Naftaly! She is currently a second year graduate student in a Clinical Psychology PhD program.


The Brain Gut Relationship in IBS

Approximately 11% of the population is affected by irritable bowel syndrome (IBS), a common functional gastrointestinal disorder that can significantly affect a patient’s quality of life.1 Functional gastrointestinal disorders can be difficult to diagnose as medical tests like blood tests and imaging scans cannot detect IBS.2 In fact, a diagnosis of IBS is IBS in textcommonly given when diseases that cause inflammation such as inflammatory bowel disease (IBD) are ruled out. IBS is thus mainly diagnosed through ruling out other diseases, and through physician use of specific diagnostic criteria called the Rome criteria.2 Since the diagnostic process can be somewhat subjective, patients with IBS tend to have high health care utilization and usually see multiple doctors before receiving a diagnosis. 3 The long process of receiving a diagnosis of IBS can be a frustrating experience for patients, on top struggling with a debilitating illness.


Psychology and IBS

Since IBS is difficult to diagnose, there is a limited understanding of how the brain and body interact in IBS (aka the mind-body connection). Research shows that stress makes IBS symptoms (e.g., abdominal pain, constipation, diarrhea) worse.4 Additionally, it is common for patients with IBS to also be diagnosed with anxiety and depressive disorders.1


Patients with IBS tend to report more frequent stressful events and have an increased reactivity to stress compared to people without IBS.4 For example, a patient with IBS who plans on going to a concert where there is little access to bathrooms, may be stressed and thus experience abdominal pain. This stressful event, however, may not be considered stressful for someone who does not have IBS.3 A patient with IBS may avoid going to the concert completely due to the fear of not having access to a bathroom. Although the patient knows that he/she is always able to find a bathroom when he/she goes out, this fear persists despite evidence that there will be bathroom access. This anxiety may even exacerbate IBS symptoms. Avoidance of attending the concert is an example of how a patient may cope with the abdominal pain and stress of going to the concert. Furthermore, avoiding the concert can contribute to depressive symptoms, feelings of social isolation, and guilt.3


The Brain and IBS

Researchers believe that there is a relationship between IBS and the brain, specifically through serotonin. Serotonin is an important neurotransmitter that is involved in mood regulation, sleep, pain, and motility in the GI system. Although some serotonin is located in the brain, guess where a majority of serotonin is located? You guessed right-the digestive tract.5 Research shows that patients with IBS may have different amounts of serotonin compared to healthy people, This could be why patients with IBS commonly also have anxiety disorders.5


Psychological Treatment and IBS

Medications like antidepressants are starting to be used as one form of treatment for IBS. Antidepressants can change the amount of serotonin in the body leading to a decrease in IBS in text twoIBS symptoms. Additionally, cognitive behavioral therapy (CBT) is a short-term treatment that involves the client and therapist (psychologist, counselor, social worker, etc) working together to address distorted thoughts and behaviors. Talking about these thoughts and behaviors can be helpful for patients with IBS.


We can use the example mentioned earlier (the patient with IBS avoiding the concert) as an example of how CBT can be used. In that example, the patient may have a cognitive distortion such as “I can’t go to the concert because I won’t make it to the bathroom.” The therapist would talk with the client about what evidence the client has that makes this thought true. Although many patients with IBS may have trouble making it to the bathroom, the therapist may find out that the client actually does make it to the bathroom on time but is constantly worried about not making it. The therapist may then have the client use thought records to help the client keep track of the accuracy of these thoughts. The therapist may also teach the client relaxation strategies, give the client homework, and help the client become more aware of inaccurate beliefs. Although talking with a complete stranger may seem scary, research shows that CBT is effective in decreasing IBS symptoms by improving patients’ coping strategies to manage stress and change cognitive distortions.3


Take home message: Although stress does not appear to cause IBS, there is a significant psychological component to IBS symptoms. Treatments like CBT and medications can be used to help decrease IBS symptoms. For more information on CBT please visit



  1. Canavan, C., West, J., & Card, T. (2014). The epidemiology of irritable bowel syndrome. Clinical Epidemiology, 6, 71–80.
  2. Dalton, C. (n.d). UNC center for functional GI & motility disorders: Ask the expert: Question what is a functional GI disorder. Retrieved from
  3. Naliboff, B.D., Fresé, M.P., & Rapgay, L. (2008). Mind/body psychological treatments for irritable bowel syndrome. eCAM, 5(1), 41-50.
  4. Drossman, D.A., Camilleri, M., Mayer, E.A., & Whitehead, W.E. (2002). AGA technical review on irritable bowel syndrome. Gastroenterology, 123(6), 2108-2131.
  5. McLean, P.G., Borman, R.A., & Lee, K. (2006). 5-HT in the enteric nervous system: gut function and neuropharmacology. Trends in Neuroscience, 30(1), 9-13.

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Can Dogs Decrease Our Stress Reactivity?

Stress research is a huge part of part of health psychology. It has been shown that it is a large contributor to heart disease, which is currently the number one killer in the United States. However, there are ways to protect ourselves from stress, with one of them being social support. Individuals who report strong social support systems live longer, have better heart attack outcomes, and report a greater sense of over all well being.

When we think of social support, we probably picture our closest friends and family. But what about our pets? Research shows that dog owners report better cardiovascular health than non-dog owners, but there may be a problem with this finding. What if dog owners have better cardiovascular health just because they walk their dog, thus giving them more exercise? This is a compelling argument, but today I will be summarizing an article that examined whether dogs can actually improve our stress reactivity. Stress reactivity is how much our body responds to a stressor; the more stressed we are, the more reactive of a stress response we have.

For this study, researchers recruited 294 college students to come into the lab and participate in the Tier Social Stress Task (a classic stress paradigm). For this task, participants were asked to give a five-minute “job talk” to three confederates. “Confederate” is a fancy term for someone on the research team who receives extensive training to act as someone else; in this case someone trained in non-verbal communication. Participants had five minutes to prepare, and then had to give the talk. They stood a few feet from the confederates, and spoke into a microphone without being able to use any notes. They were also video recorded for “future analyses” (this never actually happened, they were just made to believe it would). Confederates were trained to give looks of disapproval, and to insist participants to continue if they stopped talking before the five-minute mark.

After the talk, participants were then asked to continuously subtract 17 from 2023 until they reach 0. They had five minutes to complete this, and had to start over if a mistake was made. For these two tasks, participants were divided into one of three different groups. They were either alone, with a friend, or with a dog. The dog was a seven year old retriever and sat out of reach (but easily within view) of the participant during the tasks.

Before I get into the results, I want to briefly explain how stress physiology is measured in the lab. When we are presented with a stressor, a part of our brain called the HPA axis releases this stuff called cortisol. So the more stressed we are, the more cortisol our body releases.

Participants in the dog social support condition had lower levels of cortisol than those in the human social support and alone conditions! In other words, participants in the dog condition were less stressed than the other participants. This finding, at least to me, is pretty remarkable.

Why is this finding important? Two reasons immediately came to mind. First, we now have a reason to love our dogs even more. Beyond giving us more of a reason to spend more time exercising, we may actually respond to stressors more efficiently. A mitigated stress response leads to better cardiovascular outcomes and greater life longevity. Second, this compliments the idea of dog therapy programs. These programs provide trained dogs to people in hospitals, nursing homes, retirement homes, and disaster areas. Individuals in these situations experience great stress, and having a dog by their side during these times could greatly impact their health.

Polheber, J. P., & Matchock, R. L. (2014). The presence of a dog attenuates cortisol and

heart rate in the Trier Social Stress Test compared to human friends. Journal of

            behavioral medicine, 37(5), 860-867.