Irritable Bowel Syndrome Linked to Abnormal Brain Activity

Neuroscience and Neurology CategoryIrritable bowel syndrome (IBS) affects 10 to 15 percent of the U.S. population, predominately women, and can produce severe abdominal pain, bloating, and changes in bowel habits. No physical abnormalities can be identified on examination, and patients are often left with suboptimal symptomatic treatments and the idea that the pain is “all in your head.”

Well, maybe it is.

A new study used magnetic resonance imaging (MRI) to detect differences in brain activity in IBS patients compared to healthy ones. When predictable, mild abdominal pain was stimulated in healthy women, MRI showed decreased activity in the insula, amygdala and brainstem, areas associated with emotion and pain. IBS patients did not show decreased activity in these areas, suggesting they are hard-wired to respond more strongly to pain than others.

The idea that the errors in the perception of pain are the underlying cause of IBS has been around a long time, but this is one of the first studies to demonstrated altered brain activity in the disease. Researchers hope that this information may lead to medications targeted at the brain centers or peripheral nerves responsible for the abnormal signaling.

Patients with IBS often feel left out in the cold. Current treatments for the symptoms of IBS only work temporarily and only in some patients. Many studies have demonstrated a link between anxiety, depression and IBS. Perhaps the link lies in an incorrect, hyperactive perception of pain and danger resulting in increased sensitivity to both emotional and physical pain.

I myself have a long history of abdominal pain that fails to respond to most treatments. I’ve undergone a battery of medical tests, all with no definitive results. IBS is a diagnosis of exclusion, given when all other ausative factors are eliminated as possibilities, so I know that my pain could easily be diagnosed as IBS. And yes, the pain is more frequent and more severe when I am anxious and stressed out, as it is for many women. But that doesn’t mean the pain isn’t real, and that doesn’t mean there isn’t a real organic cause. Even if I don’t have a tumor, or an ulcer, or something else in my belly causing me pain, maybe I just have I hyperactive amygdala, and maybe future researchers will learn how we can retrain or medicate the parts of our brain that are responsible for emotional responses to pain.


Berman S, Naliboff B et al. Reduced Brainstem Inhibition during Anticipated Pelvic Visceral Pain Correlates with Enhanced Brain Response to the Visceral Stimulus in Women with Irritable Bowel Syndrome. J. Neurosci. 2008 28: 349-359.

  • dar

    T’aint in Yoor head…the medical deities Always say that for alot of diseases they can’y beat into submission with Drugs.
    Alternative medicine has achieved spectacular victories:but it requires a patient change his lifestyle;not an easy way out for sure. Diet,supplements are the key.
    Everyone,please check out Rbt Cohen’s website:
    and Andrew Saul’s

  • Pam Hampton

    While I, a woman have SBS(short bowel syndrome)(only 12 inches of small intestine after a bowel resection). I live with the same symptoms as a person with IBS. In reading this article, I have to wonder if this is happening to my husband who is extremely Bi-Polar. He has been suffering from IBS for as long as he can remember. With the mood swings from depression to homicideal episodes. When his anziety (manic) is high, his IBS just rages. He’s mentally so down on himself at these times, the depression time is when it hits the hardest.
    Thanks for the interesting article, we need to discuss this with his primary Dr as well as his phychiatrist. In connecting with the two, we may have the answer to all the tests that have came up negitave so far.

  • I appreciate your writing on this topic, which is important to many with pain and IBS. But your use of the pejorative phrase “it’s all in your head” – however well meaning in the context of the story – followed immediately by “Well, maybe it is” tends to reinforce the misconception shared by many that IBS is not a ‘real’ disorder but is, instead, as IBS suffers continue to hear over and over again, ‘all in your head.’ It would have been accurate and just as catchy to say, “Well, its not – but it is, at least in part, in your brain.”

  • Jan Patenaude, RD, CLT

    Working with IBS patients has been my specialty are for the past 6 years. I must say, it’s in the gut, not in the head for most true IBS patients. I’ve been using a blood test called a Mediator Release Test to help identify trigger foods and chemicals. (Do you know ANYBODY with IBS that hasn’t identified that diet plays a role?)

    Then, based on blood-test results, an individualized diet is set up. I’ve seen amazing results.

    The president of the company I work with was an IBS cripple prior to finding out his triggers – that’s why he went to work for the company. He figured others shouldn’t have to suffer for 35 years, as he had, when there are better answers than trial and error. (He’s happy to share his story with anybody willing to listen. Does he still have IBS? Yes – Are symptoms controlled now – yes also.)

    I’ve seen many lives restored, anxiety reduced, headaches relieved, etc. etc. As an RD since 1982, it’s the most exciting and rewarding work I’ve done since starting in the nutrition field.
    There is so much research to show that it’s not “all in your head” – but there is certainly a relationship between mediators that can cross the blood-brain barrier and symptoms, so, yes, some of it is “in the head.”

    Always happy to talk, privately if needed, with anybody. Would love to spread the word about the most effective diet therapy I’ve ever worked with!

    • I accept that you have your understanding 🙂
      I would also like to share that for two years I came off all medication and worked hard on diet and alternative therapies. I bled from the bowel every day, pretty much, for those two years.
      As the months went on, the bleeding got less. Was it the diets, or was it the fact that I was becoming happier? 🙂
      But a year later, totally free from any ‘symptoms, I had another bleeding attack 🙂 I didn’t have another two years to get well.
      I booked in to see my gastro at the hospital and more surgery was organized for two weeks time.
      But this was avoided. I changed the way that I thought, fundamentally, and that, not diet, made the complete difference.
      I can eat or drink anything I want to, however, I now choose to eat as healthy as possible, including being a vegetarian.
      I think to state that sole problem for ‘TRUE IBS PATIENTS’ is in the guts, is just your learned understanding and perception. I would now look into other possibilities for your ‘true IBS patients’, just in case you can help them in more ways other than just diet 🙂
      My ‘specialty’ has been suffering with IBS, Ulcerative Colitis and then diagnosed with Crohns Disease for 40 years 🙂 but now no more.

  • Pingback: Irritable Bowel Syndrome and the Brain Revisited | GNIF Brain Blogger()

  • travis

    Irritable bowel syndrome, commonly referred to as IBS, is believed to be caused by the dysfunction of the muscles that control the gastrointestinal tract. It is also said that these muscle dysfunctions could be caused by the nerves which control the related organs of this tract.

    The nervous control of the gastrointestinal tract is extremely complex. A system of nerves runs the full length of the gastrointestinal tract from the esophagus to the anus in the muscular walls of the organs. These nerves communicate with the nerves traveling to and from the spinal cord. Nerves within the spinal cord travel to and from the brain. Therefore, abnormal function of the nervous system in IBS may occur in a gastrointestinal muscular organ, the spinal cord, or the brain. The nervous system controlling the gastrointestinal organs, as with most other organs, contains sensory and motor nerves. Theses nerves continuously sense what is happening within the organs and relay this information to nerves in the organ’s wall. From there, information can be relayed to the spinal cord and brain. This information is received and processed in the organ’s wall, the spinal cord, or the brain. Then, based on this sensory input and the way the input is processed, responses are sent to the organ over the motor nerves. The most common motor responses in the intestine are contraction or relaxation of the muscle of the organ and secretion of fluid and/or mucus into the organ.

  • Gail R Berger

    I think that IBS can be best understood as emanating from cumulatively experienced neural responses to chronic stress, including neural responses in the CNS and neurohormone response (e.g. cortisol for negative feedback response to the initial generation of CRH and ACTH production). It is well founded in the research that environmental stress induces immediate alterations in brain activity and neurohormone response. Cumulatively and chronically experienced stress also produces later and chronic mind-body changes. The research on brain activity of later adult survivors with PTSD having histories of early childhood abuse provide a window to support this view.

    So it is in one’s head (the neural response) and also in one’s body. It is also a response to prior stressful environmental experience, including those invoiving social interactions. Please reference the research of Bruce Naliboff and Doug Drossman. Doug Drossman on UNC has done a good deal of research with IBS patients, those having active symptoms and histories of child abuse and those with active symptoms without histories of child abuse. He was able to document different brain activity in both respective populations of patients to experimentally induced distress. The impact of prior stress, including those involving stress-filled social interactions, should not be underestimated.

  • All I can do is share that I ‘had’ Crohns Disease for 40 years of my life and in the middle of a bleeding attack in 2000, I had a fundamental mind shift and the bleeding stopped in 7 days. The booked surgery for yet more bowel removal and more Prednisolone and Salazopyrin, didn’t go ahead. I was examined and released with the words “If the bleeding comes back, let us know immediately!”
    That was 13 years ago.
    Since then, I have studied and investigated as much as I could, about the brain and the way it functions and ‘thinks’:)
    I worked out the ‘stress’ (or non-acceptance of ‘what is’) was (FOR ME!) not the trigger for ‘Crohns Disease’ or IBS, but the CAUSE of the SYMPTOMS that then got named with an -itis! ‘itis’ is Latin for inflammation. What I needed to work out was, what was the cause for the inflammation? Many questions came and many were answered. One of the answers was Cortisol, which, when high levels of anxiety were held, this hormones levels were raised. This has been stated as resulting in lowered immunity and inflammatory responses in the body!!! Where does one feel anxiety, anger, fear? In the gut 🙂
    This is just my understanding and my journey. Others may not agree, especially if their only understanding is Newtonian Physics (matter) and not Quantum Physics (energy) 🙂 However, I can only go on what worked for me!

  • Pingback: Fibromyalgia – Signs & Symptoms | WEBSITEPOINT.NET()

  • Susan

    I just lost my sister to a brain bleed in the brainstem area. She was a 44 year old, healthy woman who suffered from IBS terribly. I am desperately looking for answers of what could have triggered this. She also suffered low blood pressure, and would get winded very quickly after doing exercises. I’m not trying to alarm anyone, however, after reading this article, I believe WITHOUT a doubt that IBS has a correlation with stress and abnormal brain activity. For my sister, it was in the brainstem that for no unknown reason, bleed. I will be investigating this topic. If you suffer IBS- it might be in your head. Go get checked and ask for a CAT scan.

Lindsey Kay, MD

Lindsey Kay, MD, is a medical doctor with training in pathology, and an avid writer. During his training, he worked on pre-clinical and clinical trials in a variety of laboratories related to alcohol effects on the brain, cancer diagnosis, and alternative medicine.

See All Posts By The Author

Do not miss out ever again. Subscribe to get our newsletter delivered to your inbox a few times a month.