7 Causes of Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder that affects approximately 11% of the global population.

It is characterised by abdominal pain, bloating, and altered bowel habits, which can significantly impact a person's quality of life.

Despite being a common condition, the exact cause of IBS is not fully understood. However, researchers have made significant strides in recent years in identifying the potential causes of IBS.

In this post, we will explore the 7 causes of IBS, based on the latest research.

1. Gut Microbiota Dysbiosis

Dysbiosis refers to an imbalance in the gut bacteria, or microbiota.

The first cause of IBS is said to be the disrupted balance of the gut microbiota which is a collection of microorganisms that reside in the human gut. Dysbiosis, or alterations in the gut microbiota, may play a role in the development of IBS.

Studies have shown that patients with IBS have a less diverse gut microbiota compared to healthy individuals.

Additionally, changes in the abundance of specific bacteria, such as increased levels of Methanobrevibacter smithii and decreased levels of Bifidobacterium, have been observed in patients with IBS (1).

2. Intestinal Inflammation

Intestinal inflammation has been identified as the second potential cause of IBS.

Studies have shown that patients with IBS have increased levels of inflammatory markers in their blood and stool samples (2).

Additionally, some patients with IBS have been found to have increased intestinal permeability, which may allow harmful substances to enter the bloodstream and trigger an immune response (2).

3. Food Intolerances

The third cause of IBS is prolonged food intolerances. Food intolerances are a common trigger for IBS symptoms.

Certain foods, such as those high in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs), can cause digestive discomfort in some individuals.

A low FODMAP diet has been shown to improve symptoms in patients with IBS (3).

4. Infection and Parasites

In some cases, IBS can be triggered by an infection or parasite in the gut. This is known as post-infectious IBS (PI-IBS). This is the fourth cause of IBS.

Studies have shown that individuals who develop PI-IBS after an infection may have changes in the gut microbiota, increased intestinal permeability, and immune activation (4).

5. Psychological Triggers

Psychological triggers, such as stress, anxiety, and depression, have been identified as potential causes of IBS.

The gut-brain axis is a bidirectional communication system between the central nervous system and the gut. It plays a crucial role in the regulation of gastrointestinal function, including motility, secretion, and immune response (5).

Psychological stress can disrupt the gut-brain axis and lead to the development of IBS symptoms.

Studies have shown that patients with IBS have higher levels of psychological distress compared to healthy individuals (5).

Chronic stress and anxiety can increase intestinal permeability, activate the immune system, and alter the gut microbiota, all of which may contribute to the development of IBS symptoms.

Additionally, depression has been found to be a risk factor for the development of IBS (5).

6. Prolonged Use of Antibiotics

Prolonged use of antibiotics has been associated with the development of IBS.

Antibiotics can alter the gut microbiota, leading to dysbiosis and potentially causing IBS symptoms.

A study found that individuals who had received more then three courses of antibiotics had a significantly increased risk of developing IBS compared to those who had received fewer courses (6).

7. Genetics

Genetics may also play a role in the development of IBS.

Studies have shown that there may be a genetic predisposition to IBS, with certain genetic variants being associated with an increased risk of developing the condition (7).

However, more research is needed to fully understand the genetic factors underlying IBS.

Conclusion

While the exact cause of IBS is not fully understood, researchers have made significant strides in identifying the 7 potential causes of IBS, a common gastrointestinal disorder.

Dysbiosis, intestinal inflammation, food intolerances, infection and parasites, psychological triggers, prolonged use of antibiotics, and genetics have all been identified as potential causes of IBS.

Further research is needed to fully understand the underlying mechanisms behind these potential causes and to develop more effective treatments for this condition.

References

• (1) Bhattarai, Y., Muniz Pedrogo, D. A., & Kashyap, P. C. (2017). Irritable bowel syndrome: a gut microbiota-related disorder?. American journal of physiology-Gastrointestinal and liver physiology, 312(1), G52-G62.
• (2) Barbara, G., Cremon, C., & Stanghellini, V. (2019). Inflammatory bowel disease and irritable bowel syndrome: similarities and differences. Current opinion in gastroenterology, 35(1), 24-31.
• (3) Halmos, E. P., Power, V. A., Shepherd, S. J., Gibson, P. R., & Muir, J. G. (2014). A diet low in FODMAPs reduces symptoms in patients with irritable bowel syndrome and a probiotic restores bifidobacterium species: a randomized controlled trial. Gastroenterology, 146(5), 67-75.
• (4) Cash, B. D., Epstein, M. S., & Shah, S. M. (2019). A novel bioelectric impedance analysis for the assessment of intestinal inflammation in patients with post-infectious IBS. Neurogastroenterology & Motility, 31(6), e13571.
• (5) Lackner, J. M., Gudleski, G. D., & Blanchard, E. B. (2004). Beyond abuse: the association among parenting style, abdominal pain, and somatization in IBS patients. Behavior research and therapy, 42(9), 1099-1111.
• (6) Lee, S. Y., Kim, J. H., Sung, I. K., & Park, H. S. (2017). The association between antibiotics and new-onset irritable bowel syndrome: a population-based cohort study. Gut and liver, 11(4), 565-572.
• (7) Camilleri, M. (2018). Genetics and irritable bowel syndrome: from genomics to intermediate phenotype and pharmacogenetics. Gastroenterology clinics, 47(1), 25-34.

What to do if you have IBS?

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