What is IBS?

Irritable bowel syndrome, often referred to as IBS, is a functional gut disorder affecting a large proportion of the population. IBS is characterised by chronic and recurrent bouts of abdominal pain or discomfort with a change in bowel habits. The exact cause is unknown but is thought to have a multifactorial origin in many cases.

There are four subtypes of IBS:

  1. IBS with constipation (IBS-C)
  2. IBS with diarrhoea (IBS-D)
  3. IBS with mixed bowel habits (IBS-M)
  4. IBS that is unclassified

Females are often more susceptible than males and the onset is commonly seen during adolescence1.

Symptoms can last for days, weeks or months at a time and maybe brought on by certain foods, lack of sleep or stress. The exact cause is unknown, but some people have reported that their IBS symptoms began after a course of antibiotics, a major life event, or after cases of gastroenteritis. Due to the unknown cause and number of varying cases, it is important to raise IBS awareness2.

Stress and IBS

The co-morbidity of IBS and psychological distress is common, existing in 40-60% of cases. IBS is reported to be a stress-sensitive disorder, which suggests that the management of stress can be implemented into the management of IBS. This is thought to be due to the action of the gut-brain axis which could be utilised in therapeutic strategies for the management of IBS in the future3.

The role of stress may be important in altering brain-gut interactions through the hypothalamus-pituitary adrenal axis (HPA axis). People with IBS have greater sensitivity of stress to gastrointestinal (GI) motility4. Post-traumatic stress disorder, or PTSD, has been associated with an increased likelihood of developing IBS due to the pro-inflammatory state that is experienced by people with PTSD. Similar states are seen in IBS sufferers5.

Can anxiety cause IBS?

Anxiety and depression levels are significantly higher in patients with IBS than in healthy control participants. However, the mechanism of this relationship is unclear and does not suggest causality6.

There is a suggestion in research that anxiety and depression are risk factors for IBS, with a two-fold increased risk in developing IBS in people who suffer with anxiety or depression. Promoting IBS awareness and the impact depression and anxiety have, could form a part of a management option for IBS in the future7.

IBS and gut microbiome

The gut microbiome is the collection of microbes and their DNA that inhabit the large intestine and have a beneficial effect on the host. The gut microbiome is a key regulator of the gut-brain axis and as part of this, stress.

Even short-term exposure to stress can impact the gut-microbiome profile. Dietary modulation of the microbiota with prebiotics and probiotics can reduce stress related behaviour and HPA activation8. Administration of advanced prebiotic Bimuno®, which contains a galactooligosaccharides (GOS) mixture, reduced salivary cortisol awakening response in healthy people9.

Dysbiosis of the gut microbiome can lead to activation of the immune system and low-grade inflammation in the GI tract. This could be a trigger for IBS or explain why the change in the diversity and stability of the gut microbiome is reduced in IBS patients10. The use of GOS prebiotics in management of IBS has been shown to mitigate bloating, flatulence and the associated abdominal pain, while increasing bifidobacteria11.

Management of stress to alleviate IBS

Reducing stress as part of a therapeutic strategy for people with stress-related IBS could be utilised. Mindfulness group therapy to aid stress reduction has been shown to affect quality of life, anxiety, experimental avoidance and IBS symptoms in the long-term and short-term12. Additionally, group cognitive behavioural therapy (CBT) was shown to be effective for IBS patients and could be beneficial for those IBS patients who are distressed by their symptoms13. After phone-CBT, at 24 months follow-up improvements in IBS are apparent, suggesting a recommendation of psychological therapies for IBS patients.

The effects of stress and anxiety on IBS are both associated via the gut-brain axis. The exact causality is unknown, however there appear to be associations between psychological therapies and improvements in IBS. Therefore, raising IBS awareness and the impact of the disorder can be important for patients and clinicians when choosing management paths.

Currently more research is needed to give guidance on management options for stress and IBS. Nonetheless, a focus on the gut brain axis could be utilised. This could include using prebiotics or probiotics to modulate the gut microbiome either through diet or supplementation. Another option, or as an adjunct, could be using CBT or mindfulness techniques to relieve stress and anxiety that could be triggering IBS.


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