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IBS & Fatigue: Understanding the Connection

IBS & Fatigue

IBS is a functional gastrointestinal disorder that presents symptoms such as abnormal or irregular bowel movements, abdominal pain, cramping, and bloating. 

Many IBS patients also experience fatigue on top of their usual symptoms. While researchers are still unsure of the exact cause, the leading theories range from a disruption of the gut-brain connection to certain lifestyle habits.

The Connection Between IBS & Fatigue 

According to a 2016 meta-analysis fatigue is the most frequently reported symptom of IBS that manifests outside the gut. 54% of IBS patients describe feeling “tired”, “drained” or “exhausted” in relation to their illness. Although strong evidence suggests a connection between IBS and fatigue, it remains difficult to draw a definitive, causational line between them. 

The question grows more complex when factoring in the different types of IBS (IBS-C, IBS-D, and IBS-M), the differences in IBS severity experienced by each patient, and the varying levels of IBS-related fatigue experienced by patients. Still, studies propose several potential mechanisms behind the relationship between IBS and fatigue. 

Genetic Causes 

A 2018 study discovered that women diagnosed with IBS and IBS-related fatigue had a unique mutation in their genome regulating a protein called TPH2 (tryptophan hydroxylase), which regulates serotonin levels. 

Serotonin, amongst other vital activities, is a “chemical precursor” required to produce melatonin, which is responsible for our circadian rhythms and sleep cycles. Therefore, a mutation in this protein could lead to fatigue in IBS patients. 

Increased TNF-α Levels 

A groundbreaking 2021 study examined the TNF-α (tumor necrosis factor-α) levels of both IBS and a healthy cohort and compared their mesocorticolimbic system function (the part of the central nervous system that is associated with fatigue). The study found a strong correlation between IBS patients with reported fatigue symptoms, higher TNF-α levels, and decreased mesocorticolimbic function. 

TNF-α is a known proinflammatory agent in IBS. High levels indicate the body’s inability to regulate inflammation, and decreased function in the areas of the central nervous system that regulate fatigue can make patients feel more drained than the general population. 

Lifestyle & Diet 

Stress, poor diet, not exercising enough, and not getting enough sleep are main contributors to fatigue, especially in IBS. 

A fast-paced, pressured environment causes additional stress, increasing inflammation and abdominal pain which could exacerbate fatigue. Likewise, eating foods that trigger flare-ups, or foods poor in nutritional value (highly processed fats and sugars) can leave you feeling exhausted and underfueled. 

IBS Medications 

Medications used to treat IBS, especially antidepressants, antispasmodics, and some pain medications, can cause fatigue. If you suspect your treatment plan may be causing your fatigue, consult your medical provider. They may be able to adjust your dosage or prescribe an alternative treatment. 

Managing Fatigue in IBS 

It might be worth taking a long, hard look at your nutrition, sleep patterns, and stress levels. Here are a few simple tips to get started: 

  • Make sure you eat enough of the right foods and are meeting your nutritional needs
  • Cut out foods that are difficult to digest or highly processed to reduce inflammation 
  • Develop a regular, sustainable bedtime routine to improve sleep quality 
  • Get regular exercise when you can, whether gentle yoga or cardio, to help your body regulate when and how it produces energy  

Finally, take stress relief seriously – like it’s your job! Rest when you need to, protect your energy levels, and explore methods like deep breathing or meditation to activate your parasympathetic nervous system (the body’s “rest & digest” state).

There are also herbal remedies that can help boost the body’s natural defense against the physical toll of high stress levels. Chamomile and ashwagandha are two herbal adaptogens that can improve both anxiety and digestion in IBS patients. 

Ashwagandha has additionally excelled in improving fatigue and insomnia. In fact, it may become a leading natural treatment for IBS due to its ability to lower cortisol levels (directly alleviating abdominal cramps in IBS), and improve, sleep quality, focus, and psychological well-being.  

Peppermint oil may also improve both digestive symptoms and fatigue. A 2023 animal model gave peppermint oil to rats to treat exhaustion in rats, resulting in increased performance and endurance in executing specific tasks. 

If you’re struggling to maintain lifestyle management with IBS, you can always consult with a nutritionist, sleep specialist, and/or psychologist who will help you develop diets or routines that work for your personal needs. 

Your medical provider can also help you better understand why you are experiencing fatigue with IBS, and help you develop a treatment plan that considers and addresses your fatigue. 

When to Seek Medical Advice 

If your fatigue lasts more than a few days (think 2-3), you experience difficulty in completing daily tasks, or you have been losing weight, you should see a doctor as soon as possible to rule out a medical complication. If you are also experiencing shortness of breath, nausea, an irregular heartbeat, or depression, you should seek immediate medical attention. 





This blog is not intended to provide diagnosis, treatment, or medical advice. The content provided is for informational purposes only. Please consult with a physician or healthcare professional regarding any medical or health related diagnosis or treatment options. The claims made regarding specific products in this blog are not approved to diagnose, treat, cure, or prevent disease.


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