Irritable Bowel Syndrome in Fibromyalgia & ME/CFS

Why Do They Go Together?

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Fibromyalgia (FMS), chronic fatigue syndrome (ME/CFS) and irritable bowel syndrome (IBS) frequently go together. No one really knows why, but we do know that all three conditions can include imbalances of the chemical serotonin -- although in fibromyalgia (FMS) and chronic fatigue syndrome  it's an imbalance in the brain, while with IBS it's in the gut.

Like FMS and ME/CFS, IBS by itself can be debilitating and can impose a lot of restrictions on your diet and lifestyle.

Anything that causes pain or stresses your body can exacerbate FMS/ME/CFS symptoms, so it's especially important to treat your IBS. With some effort, IBS symptoms typically can be well managed.

What is Irritable Bowel Syndrome?

People with IBS can have urgent diarrhea or constipation, or can have alternating bouts of each. They also have frequent abdominal pain. While most people with FMS don't have abdominal pain, IBS pain feels similar to the pain of FMS.

When you have IBS, your intestine does not function properly. The intestine itself is fine, but some people may have a lower pain tolerance when it comes to intestinal stretching and movement, or they could possibly have disordered intestinal muscle movement.

Researchers don't yet know why IBS develops, but they do know that it often starts after severe gastroenteritis (so called "stomach flu") or an extremely stressful event. Researchers currently are looking into what's called the brain-gut connection in order to better understand the relationship between stress and IBS.

Why Do These Illnesses Go Together?

The short answer to the question of why these conditions often occur together is, "Nobody knows." The long answer is, at this stage, speculative. Similarities that bear looking at include:

  • All three conditions may involve serotonin imbalances,
  • IBS and ME/CFS both can begin after another illness,
  • IBS and FMS both are strongly linked to stress.

Right now, we don't know the underlying causes of any of these conditions, and we likely won't understand their relationship until we better understand their causes and mechanisms. However, based on research, an emerging umbrella term is central sensitivity syndromes.

IBS Symptoms

Symptoms of IBS include pretty much any unpleasant abdominal symptoms you can think of. Along with constipation and/or diarrhea, major symptoms are:

  • Nausea and vomiting,
  • Gas,
  • Bloating,
  • Abdominal distention.

Symptoms NOT associated with IBS include:

  • Bloody stool,
  • Anemia,
  • Pain and cramping that wakes you up or keeps you awake,
  • Significant, unintentional weight loss.

Any time you have a marked change in bowel function, talk to your doctor.

Diagnosing IBS

Another thing IBS has in common with FMS and ME/CFS is that it's a diagnosis of exclusion, meaning it has to be made based on symptoms rather than tests. Your doctor may need to rule out inflammatory bowel disease (ulcerative colitis and Crohn's disease) and colon cancer before diagnosing IBS.

IBS Treatment

IBS generally is a chronic condition, but you have a lot of options for feeling significantly better.

Drug treatments for IBS generally include:

Sticking to a treatment regimen can minimize your symptoms, which means they'll have much less impact on your FMS or ME/CFS.

Having Irritable Bowel Syndrome & FMS/ME/CFS

When you're dealing with multiple conditions, make sure all your doctors and your pharmacist are aware of the medications, supplements, and dietary limitations you face.

The good news is that IBS treatments don't generally conflict with FMS/ME/CFS treatments, and the focus on a healthy diet can be beneficial to your overall health.


British Medical Journal. 1997 Mar 15;314(7083):779-82. "Prevalence of gastrointestinal symptoms six months after bacterial gastroenteritis and risk factors for the development of the irritable bowel syndrome: postal survey of patients."

Gut. 1992 Jun;33(6):825-30. "Effects of stressful life events on bowel symptoms: subjects with irritable bowel syndrome compared with subjects without bowel dysfunction."

The Journal of the American Medical Association (2006) 295:960. JAMA Patient Page: Irritable Bowel Syndrome.

Journal of Psychosomatic Research. 2008 Jun;64(6):573-82. "Somatic comorbidities of irritable bowel syndrome: a systematic analysis."

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