Is irritable bowel syndrome real or just a symptom cluster?

Irritable bowel syndrome, or IBS, is a disorder of the large intestine that leads to gas, bloating, pain, diarrhea, or constipation. In the US, there are 200,000 cases of IBS every year. Thus, it’s relatively common.

People with IBS often have a hard time getting effective treatment for the condition. As a result, people suffer with the symptoms for long periods of time. Often times, people just manage the symptoms as there is currently no cure.

What makes irritable bowel syndrome a tough nut to crack is that there is no specific cause. In fact, it’s a diagnosis of exclusion. This means that if a doctor rules out other GI disease, they diagnose people with these symptoms with IBS.

But what if IBS isn’t a clinical entity? What if it’s a group of symptoms that seem to pair together when something goes wrong in the gut? What if, as I have suggested a few times, that IBS is simply chronic disease of the gut?

A new review out in Gastrointestinal Disorders makes the case that we should not view IBS as a specific disorder. Rather, it’s a group of symptoms that pop up in the gut due to various causes. There are different causes of these symptoms. And when you find the cause and treat it, the symptoms go away.

This implies that treating IBS as a clinical entity is a mistake. Thus, let’s take a look at the review titled, Does irritable bowel syndrome exist? Identifiable and treatable causes of associated symptoms suggest it may not.

Irritable bowel syndrome

Irritable bowel syndrome: A new look

It’s important to point out that this review doubt that people with IBS have symptoms. It’s clear the symptoms are real. Hence, the author is not implying that it’s all in your head.

Research in to IBS shows that there are many ways to get to this symptom cluster. The basic pathway to IBS symptoms goes through 2 distinct problems with many causes. These problems are altered gut motility and altered sensory function in the gut.

The different causes vary based on the individual, their lifestyle, and their genes. Therefore , an individualized treatment approach takes these factors in to consideration.

Support for this hypothesis comes from a couple of studies. Both found that more than 90% of patients diagnosed with IBS-D had an underlying cause. As a result, treating the underlying cause(s) improved their symptoms, or eliminated them altogether.

These 2 studies indicate that since each person gets to IBS in a different way, treating it as a single clinical entity is a mistake. Thus, a functional medicine approach treating each person as an individual is best.

Irritable bowel syndrome causes

The author of this review breaks the cause of irritable bowel syndrome in to 3 distinct categories: Lifestyle/Environmental, nutritional factors, and functional imbalances. Below is a short description of each with a focus on the lifestyle factors.

Lifestyle/Environmental causes


Stress and anxiety are well known factors that pair with IBS. This relationship is bi-directional with stress affecting IBS and vice versa.

Stress can be from genetic susceptibility and previous or current life experiences. The author states, “…low stress resilience has been found to predict IBS symptom severity.” Therefore, managing stress is critically important in IBS.

Circadian disruption

Circadian rhythms play a big role in regulating many gut functions. Chief among them are gut motility and sensory function. A simple way to think about it is circadian rhythms help the gut tell time.

Our behaviors help the gut tell time. As a result, many of our behaviors tell the gut the wrong time. Consequently, when the gut doesn’t know the time, it doesn’t know when to turn on off for repairs. This causes our gut to malfunction as damage exceeds repair.

Physical inactivity

Physical inactivity is undervalued as a regulator of gut function. In and of itself, physical activity directly regulates gut function. Above all, by optimizing circadian rhythms and making us more resilient to stress.

There’s also evidence that muscle signaling molecules promote gut health. And exercise alters the gut environment which promotes a healthy gut and microbiome.

Vitamin D deficiency/Sun exposure

Vitamin D plays an important role in gut function. It regulates factors such as

  • Intestinal permeability
  • Inflammation
  • The microbiome.

As a result, people with IBS typically have lower serum vitamin D levels.

The author actually has vitamin D listed as a nutritional problem. I consider it a lifestyle problem as we should get vitamin D from Sun exposure. Furthermore, there’s evidence that other aspects of Sun exposure have a beneficial effect on the gut,

Nutritional factors

Nutritional factors that contribute to irritable bowel syndrome center around individual food sensitivities. These can be temporary or permanent depending on the cause. When genes are the cause they’re permanent. But when the cause is environmental(Leaky gut/dysbiosis), reversal may happen.

Different sensitivies/intolerances discussed include:

  • Carbohydrate intolerance
  • Lactose intolerance
  • Non-celiac gluten sensitivity
  • Nickel sensitivity
  • Intolerances to other foods

Working with a functional medicine practitioner to identify food intolerances is crucial. Consequently, treating the underlying cause heals the gut. If it’s genetic, a long term individualized diet is necessary. If it’s environmental, a short term elimination diet helps. However, reintroducing the food is important after correcting the factor driving it.

Behavioral factors that can drive food sensitivity are:

  • Circadian disruption
  • Heavy antibiotic use
  • Chronic hyperglycemia
  • Gut inflammation

These factors often drive leaky gut or dysbiosis, which impair the immune system in the gut and beyond. Therefore, elimination diets should be temporary in nature unless genetic in nature.

Functional imbalances

The functional imbalances that cause IBS include:

  • Poor pancreatic enzyme output
  • Low grade chronic inflammation
  • Leaky gut
  • Chronic constipation
  • Dysbiosis
  • SIBO
  • Parasitic infection/overgrowth

Identifying these requires testing by a functional medicine practitioner. Even more important is using an integrative approach to treat the cause. An integrative approach addresses:

  • Lifestyle factors
  • Genetic factors
  • Dietary factors

Furthermore, a good treatment plan includes an implementation plan for the individual. Similarly to any other sort of lifestyle modification program such as weight loss, we are bad at change. Particularly when it comes to reversing bad habits.

Changing habits is difficult, and most people need to know how they are doing to stay motivated. Also, it’s a good idea for people to see what they do right and what they do wrong.

Finally, regular assessment periods indicate progress and guide the direction of treatment.


Irritable bowel syndrome is currently treated as a specific clinical entity. This is a mistake given much of the current research. Instead, IBS may be a convergence of symptoms that come about when motility and sensory perception are impaired in the gut.

Because the underlying causes of poor motility and sensory function are many, there will never be a single treatment approach for IBS. Clinicians should assess each individual with an intake form that looks at:

  • Lifestyle factors such as circadian rhythms, sleep and physical activity
  • Genetic factors that affect dietary need and sensitivity
  • Functional imbalances that impair the gut

These factors are not isolated from one another. Instead, they should be viewed as inter-related and addressed accordingly. In other words, addressing them together yields the best results.

This blog focused on the lifestyle factors that lead to IBS for a few reasons. First, addressing lifestyle doesn’t necessarily require a doctor’s help.

Secondly, lifestyle factors may be the driving force for food intolerance and functional imbalances. Several people in my Circadian Retraining Program and Stop Leaky Gut Challenge have reversed both simply by addressing their lifestyle.

Finally, this blog is about the lifestyle aspect of gut health. Based on my experience, it’s driving a lot of gut problems, particularly in Type 2 diabetics. One of the central problems in Type 2 diabetes is chronically high blood glucose, which damages the nerves responsible for motility and sensory function in the gut. And this happens in everyone, not just Type 2 diabetics.

This is an open access paper so you can check out the testing and solutions for the other factors by clicking the link at the beginning of the blog. However, I implore you to see a functional medicine practitioner to address them rather than flying blindly and treating yourself. .

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