IBS & Migraines: Why Do I Have Both?

The connection between your gut and your migraines

woman suffering from migraine in bed
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Irritable bowel syndrome (IBS) and migraines are two different pain-related disorders, and yet they share some features. This suggests a possible common origin—like individual branches of a tree stemming from a common root.

In fact, it's common for people with IBS to also have migraines and vice versa. Often people identify more with one disorder, usually the one that is more painful or debilitating.

IBS and Migraines as Central Sensitivity Syndromes

Many experts suggest that both migraines and irritable bowel syndrome are central sensitivity syndromes.

"Central" refers to pain that arises from a change in the central nervous system, which comprises the brain and spinal cord.

"Sensitivity" refers to the fact that people with migraines and IBS have a heightened sensitivity to both stimuli that should and should not hurt, meaning they feel a higher level of pain than normal with a needle prick (hyperlagesia) or even discomfort with regular touch (allodynia). 

Central Sensitivity in Migraines

During a migraine attack, scientists believe that blood vessels surrounding the brain dilate. This artery dilation or widening activates the trigeminal nerve (a cranial nerve) to release peptides like calcitonin gene-related peptide (CGRP), which promotes inflammation and transmits pain signals to the brain—this is referred to as the trigeminovascular pain pathway.

Eventually, the brain becomes sensitized to the triggers, meaning nerve cells in the brain can more easily transmit messages through the trigeminovascular pain pathway because they have done it before. This is called central sensitization and can cause migraine attacks to arise more easily with exposure to the same trigger.

Central Sensitivity in IBS

The hallmark of IBS is visceral hypersensitivity, meaning that the internal organs of a person (e.g., intestines, stomach, bladder) cause an increase in pain sensation. This is why mild stomach bloating or distension in a person can be excruciating and debilitating for someone with IBS.  

Experts believe that the visceral hypersensitivity of IBS eventually leads to sensitivity within the central nervous system. This would explain why many people with IBS suffer from extraintestinal pain-related symptoms (e.g., migraines, joint, and muscle pain) and some do not.

Other Central Sensitivity Syndromes

Other disorders commonly classified as central sensitivity syndromes include:

  • fibromyalgia
  • chronic fatigue syndrome
  • chronic pelvic pain
  • interstitial cystitis

Like these other disorders, IBS and migraines are diagnosed by their symptoms, meaning there is no lab or imaging test to confirm it. Rather there are criteria that doctors use to determine whether a patient suffers from it—sort of like a check-list of symptoms, but a bit more detailed.

 

The Estrogen Link: IBS and Migraines

Besides a heightened central sensitivity, both IBS and migraines are more common in women. This suggests that sex hormones, especially estrogen, influence these pain disorders.

IBS and Estrogen 

In IBS, estrogen not only modulates the pain and stress response in the brain, but it also affects the sensitivity of your gut to pain, the motility of your gut's contents, and even the type of bacteria that grow in your gut.

That being said, the role of estrogen in IBS is complex. This is why studies are conflicting as to whether certain hormone-sensitive stages in a woman's life help or worsen her IBS symptoms. For example, studies mostly show that the incidence of IBS is lower after menopause, when estrogen levels in the body are very low. That being said, some women report worsening GI symptoms, especially constipation and bloating, after menopause.

Migraines and Estrogen

In migraines, women typically have improvement in their migraines during the second and third trimester of pregnancy when their estrogen levels are high. Likewise, menstrual migraines are common in female migraineurs and are believed to be triggered by an estrogen drop, which occurs just before menses.

By the same token, many women experience more migraines as they approach menopause, when their ovarian function begins declining and estrogen levels in the body start falling. That being said, their migraines seem to improve after menopause—a somewhat confusing picture, suggesting a number of factors at play. 

Other Common Features of IBS and Migraines

It's common for psychiatric disorders like depression, anxiety, and/or post-traumatic stress disorder to co-occur with IBS and migraines. Having a psychiatric illness in addition to a pain disorder is an intricate cycle of one triggering the other. It's often difficult to ascertain which came first, the "chicken versus egg" theory. Regardless, the combination of bodily pain along with psychological disturbances can worsen a person's quality of life and daily functioning.

In addition, science is now emerging that people with IBS and migraines may share common genes, specifically those related to serotonin. This link is interesting because it may help scientists create more targeted therapies for both IBS and migraines. 

Treating Your IBS and Migraines

To treat both conditions, physicians commonly recommend a combination of therapies including medications and behavioral therapies, like biofeedback or cognitive-behavioral therapy. In addition, complementary therapies, like acupuncture, are often utilized by patients to augment their pain relief. 

Scientists are also looking into single treatments that can help both conditions, one being diet therapy. In one small 2013 study in Headache, participants with both migraines and IBS underwent an elimination diet, based on high IgG levels in their bloodstream when exposed to certain foods. IgG is an antibody and a marker for inflammation in the body. The diet reduced both symptoms of IBS and migraines in the participants. 

Bottom Line

A connection between two disorders does not mean that one causes the other, or that having one means you will you eventually develop the other. It simply means that there is a link.

Studying the links between IBS and migraines helps scientists better understand why these pain disorders develop and how doctors can best treat them—a slow process that requires careful and delicate interpretation and study.

Sources:

Aydinlar El et al. IgG-based elimination diet in migraine plus irritable bowel syndrome. Headache. 2013;53(3):514-25.

Chang F-Y, Lu C-L. Irritable bowel syndrome and migraine: bystanders or partners? J Neurogastroenterol Motil. 2013;19(3):301-11.

Moshiree B, Zhou Q, Price DD, Verne GN. Central sensitisation in visceral pain disorders. Gut. 2006;55(7):905-8.

Mulak A, Taché Y, Larauche M. Sex hormones in the modulation of irritable bowel syndrome. World J Gastroenterol. 2014;20(10):2433-48. 

Uluduz D et al. A link between migraine, tension type headache and irritable bowel syndrome: Clinical and genetic indicators. Neurology. 2016;86(16)SupplementP4.120.

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