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4 Root Causes of IBS

In my recent instagram posts I've been discussing how the diagnosis of IBS - Irritable bowel syndrome - is often a 'cover all' diagnosis. Historically IBS has been considered an exclusion diagnosis. Meaning they have tested you and ruled out major conditions such as Crohn's or Ulcerative Colitis. Although this is useful to know, it doesn't tell you what is driving your digestive issues.

In functional medicine the key is doing the detective work to find those root causes, figuring out what's at the centre of your issues and healing holistically back from there.

So with that being said, what are some major driving forces of IBS?

Here are 4 root causes I often see in clinic:

1. Microbiome Imbalance

The microbiome is made up of trillions of bacteria (and other microbes) that play a large role in our health. Influencing things like our immune system, metabolism and nervous system, it's important they stay healthy and in balance.

However, many aspects of modern life can throw off this careful balance and contribute to IBS symptoms. Antibiotics are a large factor to consider for microbiome dysbiosis. Antibiotics are the big guns that go in and kill off all bacteria; the negative one's causing issues but also the good ones that we need. (1)

A study from 2011 actually found that restoring the good bacteria via probiotics after a course of antibiotics relieved IBS symptoms, especially antibiotic related diarrhoea, by a minimum of 37%. (2)

Many other factors can affect the state of our microbiome such as stress, poor diet and medication. Getting our microbiome in balance is a large part of healing IBS issues.

2. Leaky Gut

The epithelial cells that line our intestines contain an important u-shaped tissue called Tight Junctions. These tight junctions act as a seal between the cells inside the intestine and the bloodstream, they allow certain molecules to pass through such as nutrients and minerals but prevent unwanted molecules to pass through such as toxins or pathogens. (3)

Leaky gut, also known as intestinal permeability, refers to a break down in these tight junctions. They have become weakened and are no longer so 'tight'! Because of this, molecules can now flow more freely through to the bloodstream, particularly toxins and macromolecules (foods that haven't been fully broken down), causing your immune system to step in and initiate a response to these intruders in the bloodstream. This causes inflammation and can be linked to multiple digestive and IBS issues. (4)

Looking into leaky gut could be the solution to your IBS problems!

3. SIBO, Infections and Parasites

Gut infections are more common than you think, although chronically under-diagnosed, parasites picked up from travel, undercooked food or even our pets can be to blame. (5) Some studies also show that 84% of IBS sufferers have SIBO; Small Intestinal Bacterial Overgrowth. (6) Highlighting the importance of keeping your gut bacteria in balance, a perfect harmony of healthy bacteria for a strong digestive system.

Pathogens are part of daily life, and our gut in its most ideal state should be robust and able to fight off infection. However, years of stress, poor diet and neglect can leave it in a compromised state, unable to fight the good fight. This gives way to infection taking hold, driving up inflammation and digestive issues. A large part of functional medicine is to run tests, find what infection could be driving your symptoms and tackle them head on.

4. External Factors

Over time our gut can be impaired by chronic neglect. Foods such as refined sugar, vegetable oils, gluten and fried foods can drive up inflammation, especially if paired with an already leaky gut, and over time weaken our digestive system. On top of this, certain infections in the gut, such as the fungi - Candida Albicans feed off sugar. (7)

Stress is a key player when it comes to an impaired gut. The largest nerve in the body is called the vagus nerve, stretching from the brain to the large intestine. This highlights the link directly between the brain and the gut, and in its simplest form when the brain isn't happy the gut isn't happy, and unfortunately vice versa. Managing stress and caring for our nervous system can be fundamental in IBS. (8)

Many other external factors can have a negative effect on our gut and therefore IBS symptoms, factors such as smoking, medications and external toxins like mould and chemicals.

Our gut is so important, in fact it was Hippocrates who said 'All disease begins with the gut.' With 70% of our immune system being located in the gut and knowing that 90% of our serotonin is made in the gut this only goes to show just how crucial it is to have a happy and healthy digestive system.

So hopefully you can see the picture I'm trying to paint of how the above, or more often than not, a mixture of the above can be what's lying underneath that IBS diagnosis.

Note that where I've mentioned foods it's around those that cause inflammation. Unless you have an allergy to a food it's unlikely you need to cut it out completely for life. Remember FODMAP or any elimination diet should only ever be temporary. By finding your root cause, we can work on bringing resolution to that area, healing the gut and then you can live life like normal, restriction free!

If you're struggling with IBS or a constant barrage of digestive issues and you're done trying to figure it out alone, get in touch via the button below and let's chat about it!

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1. Ramirez et al. Front. Cell. Infect. Microbiol., 24 November 2020. Sec. Microbiome in Health and Disease. Volume 10 - 2020

2. Hickson M. (2011). Probiotics in the prevention of antibiotic-associated diarrhoea and Clostridium difficile infection. Therapeutic advances in gastroenterology, 4(3), 185–197.

3. Lee S. H. (2015). Intestinal permeability regulation by tight junction: implication on inflammatory bowel diseases. Intestinal research, 13(1), 11–18.

4. Hanning, N., Edwinson, A. L., Ceuleers, H., Peters, S. A., De Man, J. G., Hassett, L. C., De Winter, B. Y., & Grover, M. (2021). Intestinal barrier dysfunction in irritable bowel syndrome: a systematic review. Therapeutic advances in gastroenterology, 14, 1756284821993586.

5. Shafiei, Z., Esfandiari, F., Sarkari, B., Rezaei, Z., Fatahi, M. R., & Hosseini Asl, S. M. K. (2020). Parasitic infections in irritable bowel syndrome patients: evidence to propose a possible link, based on a case-control study in the south of Iran. BMC research notes, 13(1), 264.

6. Lacy, Brian E. PhD, MD, FACG1; Pimentel, Mark MD, FACG2; Brenner, Darren M. MD, FACG3; Chey, William D. MD, FACG4; Keefer, Laurie A. PhD5; Long, Millie D. MDMPH, FACG (GRADE Methodologist)6; Moshiree, Baha MD, MSc, FACG7,” ACG Clinical Guideline: Management of Irritable Bowel Syndrome,” The American Journal of Gastroenterology: January 2021-Volume 116

7. Bolte LA, Vich Vila A, Imhann F, et al

Long-term dietary patterns are associated with pro-inflammatory and anti-inflammatory features of the gut microbiomeGut 2021;70:1287-1298.

8. Özçağlayan, Ö., Kurtoğlu Özçağlayan, T. İ., Doğru, M., & Mete, R. (2020). Vagus nerve assessment via ultrasonography in irritable bowel syndrome. Are there any changes of dimension in the vagus nerve?. The Turkish journal of gastroenterology : the official journal of Turkish Society of Gastroenterology, 31(7), 503–507.


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