Irritable bowel syndrome (IBS) is a huge problem that affects about 10 to 23 per-cent of people worldwide. It is one of the most common reasons for visits to the doctor, costing the NHS around £12 million in lost productivity and health care costs annually. As healthcare practitioners we know that IBS is a complex condition with multiple contributing factors, including digestive imbalances and mal-absorption issues, disruptions in gut homeostasis, and of course lifestyle and environmental factors, including stress. For those diagnosed with IBS, the pathophysiology includes an altered gut microbiome, increased inflammation and intestinal permeability, and systemic immune reactivity.
Many people with IBS have been dismissed with the idea that it’s ‘all in their heads’ - that if they could just reduce their stress levels, their IBS would go away. Whilst this is an obvious oversimplification, the role of stress as a contributor to IBS is an important part of the clinical picture. So, what is the link between stress and IBS?
IBS is a stress-sensitive disorder, meaning that stress-induced alterations in neuroendocrine immune pathways can cause symptom flare ups or an exaggeration of IBS. This can happen through several mechanisms.
Experimental studies suggest that acute stress activates mucosal mast cells, which in turn release neuropeptides such as proteases and pro-inflammatory cytokines which are known to be mediators of the altered intestinal motility, secretion and permeability that is characteristic of IBS.
Repeated exposure to chronic stress can lead to long-term changes in the gut microbiota. Chronic stress can induce dysbiosis and enhanced bacterial wall adherence, suggesting that stress-induced microbiota alteration of the gut also plays a critical role in the pathogenesis of IBS. Chronic stress also reduces stomach acid secretions, which can lead to changes in PH downstream in the intestines which can in turn contribute to bacterial overgrowths like SIBO and of course, IBS symptoms.
A disturbance to the gut-brain axis has been recently recognised as a conceptual model of IBS pathophysiology. It’s possible that ‘irritable brain’ may be causing irritable bowels - and vice versa. ‘Irritable brain’ symptoms like stress, anxiety and depression and IBS do often occur together. The gut-brain axis is bidirectional, so an approach that addresses both gut-located features of IBS such as gut flora imbalances as well as systemic factors such as stress management and resilience techniques is going to offer a valuable clinical approach.
Chronic stress is known to affect serotonin levels. Serotonin is associated with gut functions including assimilation and absorption, gut motility, secretion, visceral hypersensitivity, and inflammation, as well as regulation of fluid discharge in the gut. Deficiency has been identified as a prominent factor in IBS.
It’s also worth clarifying what is meant by stress in the context of IBS. Stress is a reaction to any event or situation, real or imagined, that causes physiological and psychological consequences. Whether it’s external stressors from work, relationships or finances, or internal stressors generated by negative thought patterns and rumination, these factors can all trigger the biochemical changes that precede IBS flare ups.
Our cultural definition of stress is often quite narrow, usually being limited to the idea that stress is primarily a feeling of mental/emotional pressure and overwhelm. In reality, many stressed individuals don’t identify with this definition, and don’t necessarily consider themselves stressed at all. Stress denial is quite common as a response to overwhelm, but this denial doesn’t negate the underlying physiological response to stress, even if the client in question insists they’re not stressed, or they’re coping just fine.
Stress is unavoidable, but there is much that can be done to reduce the harmful effects of chronic stress and improve stress resilience.
• Seeking help with a talking therapist can be helpful in addressing any negative thought patterns and beliefs that may be contributing to stress.
• A daily meditation practice can help decrease negative mood states, enhance attention and working memory, and help decrease anxiety.
• Using apps can help support daily stress management practices such as movement and mindfulness practices, though they shouldn’t be solely relied on - it’s also advisable to attend classes, work with an expert or develop independent practices.
• Engaging in relaxation practices on a regular basis can help to manage stress levels. Watching TV is not necessarily relaxing to the nervous system, and can often be a way of distracting from anxiety without actually addressing it. Magnesium baths, sauna and breath work practices are all useful options.
• Exercise with a VO2 max of 40% actually clears cortisol - meaning that low intensity exercise like yoga or walking is a great option for reducing stress levels.
This is not an exhaustive list, and there are plenty of other ways to cultivate resilience in addition to personalised nutritional stress support.
Whilst stress is often implicated in the pathogenesis of IBS, it is far from being the only culprit. Other potential mediators include SIBO and SIFO, dysbiosis, digestive insufficiencies in bile acid, adverse food reactions and acute GI infections. Lifestyle factors such as stress affect both the development and severity of IBS. Research suggests that negative emotions, such as anxiety, play a major role in GI functioning due to the bidirectional communication between the gut and brain. The relationship between stress, emotional regulation and IBS continues to be an important area of research.