In this article, Dr Sula Windgassen explores the relationship between psychological factors and physical symptom severity in cognitive behavioural therapy as a treatment for irritable bowel syndrome (IBS).
- IBS is considered to have a ‘biopsychosocial’ aetiology, whereby physiological, psychological and social factors have a role in the onset and maintenance of IBS.
- Nevertheless, first-line treatment in general practice remains heavily weighted towards pharmacological treatments such as antispasmodics or low-dose tricyclic antidepressants.
- A recent study with individuals with refractory IBS compared three conditions across a range of outcomes, including symptom severity, impact on life, anxiety and depression for CBT-focused treatment of IBS.
- This showed large statistically significant and clinically meaningful improvements in IBS symptoms in addition to impact on life when managed via CBT.
Irritable bowel syndrome (IBS) is estimated to affect up to 22 per cent of people in the UK, with similar prevalence rates across Europe and the US. Symptoms of IBS include pain and/or discomfort in the abdomen, which people may experience in different ways including cramps, consistent pain or bloating, and changes to bowel movements. People may experience looser stools and increased frequency (diarrhoea), or constipation. There may also be an alternation between these two bowel patterns. No one physiological factor underpins the development and experience of IBS. Although it is agreed that the way the bowel functions is altered, there is little evidence to suggest one underlying pathophysiological cause. Instead, IBS is considered to have a ‘biopsychosocial’ aetiology, whereby physiological, psychological and social factors have a role in the onset and maintenance of IBS (Drossman, 1996).
Nevertheless, first-line treatment in general practice remains heavily weighted towards pharmacological treatments such as antispasmodics or low-dose tricyclic antidepressants. Fibre supplements may also be prescribed where individuals are experiencing constipation. Increasingly, there is a move to prescribe the FODMAP diet. There is some controversy around this, as patients with IBS are commonly very diet-focused, experiencing a high degree of limitations on their everyday life as a result. Recently, Kevin Whelan, Professor of Dietetics at King’s College London, emphasised the FODMAP as a temporary diet, not intended to be a life-long diet, and needing the input of registered and trained dietitians to facilitate its implementation.
Currently, the National Institute for Health and Care Excellence (NICE) guidelines recommend psychological therapy, specifically cognitive behavioural therapy (CBT) only where symptoms persist for 12 months. There is compelling empirical evidence establishing the efficacy of CBT for IBS in reducing symptom severity in addition to reducing impairment on life (Ford et al, 2014). For many people, first-line treatments do not adequately reduce symptoms. For this population of individuals with ‘refractory IBS’, it can be incredibly demoralising and a daunting process to try and self-manage symptoms.
A new perspective
I worked on a recent study funded by the National Institute of Health Research, which was the largest randomised controlled trial of CBT for IBS (558 participants) to date (Everitt et al, 2019a). Individuals included in the study met criteria for refractory IBS. The study compared three conditions across a range of outcomes, including symptom severity, impact on life, anxiety and depression. The two treatment conditions involved the same content and remotely delivered CBT. In the higher-intensity condition, participants worked through a patient manual at home and there was a higher degree and duration of therapist facilitation over the phone (8 hours in total, with up to two 1-hour booster sessions). In the lower-intensity condition, participants predominantly worked through the CBT intervention on their own, using the interactive website. They also received phone support, but this was for 30 minutes instead of 60 and there were fewer sessions (three 30-minute sessions with two 30-minute booster sessions). The last condition was a control ‘treatment as usual’ condition.
Both the treatment conditions showed large statistically significant and clinically meaningful improvements in IBS symptoms in addition to impact on life. These results were maintained at 12 months. A further follow-up at 24 months, and published in The Lancet Gastroenterology & Hepatology, showed ongoing benefits for trial groups as compared with the treatment as usual group (Everitt et al, 2019b).
Cognitive behavioural therapy and symptom severity
While working on this trial part time, I completed my PhD, which aimed to assess the mechanisms by which CBT had effect on symptom severity and impact on life. As is typical of a PhD, I started my research by conducting a systematic review. I looked for papers reporting on therapeutic mechanisms across different psychological interventions for IBS, not just CBT. However, there was a limited number of studies investigating therapeutic mechanisms, and those that did were largely doing so in the context of CBT-based studies. The results of the review suggested that therapies improved symptoms and reduced impact on quality of life by changing illness-related thinking, anxiety specific to the experience of gastrointestinal symptoms and behavioural responses to symptoms.
To build on this empirically, I applied mediation analysis to data collected previously for a trial assessing the efficacy of CBT in addition to antispasmodics for IBS (Kennedy et al, 2005). This assessed the causal paths between treatment and outcome. The models that fit the data best showed that change in IBS-specific thinking occurred during therapy, which produced a change in anxiety and subsequently in symptom severity and impact on life (Windgassen et al, 2019). Similarly, models demonstrated that behavioural change related to symptoms preceded reduction in anxiety and, subsequently, the two outcomes of symptom severity and impact on life. The take-home message from these findings is that the way we think about our symptoms in IBS and the way we respond to them have an impact on how severely we experience them, both physically and in terms of the impact they have on our life. These findings supported the CBT model of IBS that have been developed previously by both Professor Rona Moss-Morris and Professor Trudie Chalder at King’s College London.
The link between brain and gut
How can the relationship between psychological factors and physical symptom severity be understood? There is increasing research demonstrating the link between the brain and the gut. The enteric nervous system is a network of around 100 million neurons located in the gut. It is known as the second brain due to the similarity it shares with the brain and the fact that it can operate autonomously from it. The language we use is demonstrative of the closely experienced link between brain and gut: ‘gut feeling’ describes the immediate sensory response we get in the stomach in relation to something we are thinking about.
Growing research demonstrates a close and direct link between psychological events and gut functioning, via the ‘brain-gut axis’. This can involve pathophysiological mechanisms such as the dysregulation of the gut microbiome.
Providing individuals with an understanding of how the gut works and the role of the brain and nervous system in bowel functioning is an important starting point for CBT in IBS. This involves socialising clients to the ‘vicious cycle’ between stress and symptoms. Consider Tom, for example. He experiences a tummy bug, which causes diarrhoea and stomach pain. His routine is disrupted. The bug finally starts to clear, but Tom still feels too sensitive to eat as he used to, experiencing cramping when he tries to eat. He therefore eats irregularly, which means that his digestive system does not have a chance to regulate itself. This response maintains cramps and/or bouts of diarrhoea and constipation. It is at this point that Tom worries about his health and about something being wrong. This worry exacerbates his symptoms both directly, through the brain-gut connection, and indirectly, as he focuses more on his symptoms, changes his eating and activity patterns and starts avoiding things.
Once clients are familiar with this cycle and the close relationship between the brain and the gut, they are guided to explore how their own vicious cycles appear. This involves a symptom diary, which records responses to symptoms as well as stress. This is really useful for understanding what kinds of behavioural responses to symptoms may actually be maintaining them. In CBT, we focus less on what people eat and more on how they eat. Big gaps between meals and irregular eating patterns are quickly identified as things to change. Exercises to increase bowel control are also introduced early on in therapy.
Changing key behaviours to improve health
In CBT generally, but particularly for health conditions, it is common to start working on changing some key behaviours first, as this provides a window of understanding and belief in the therapeutic model. Seeing is believing! People are then more open to start looking more directly at the role of their thoughts in their experience. With IBS, a good place to start is by presenting common myths about the bowels and symptoms. It is a common misconception that irregularity is a sign of poor health or that being constipated is toxic for the body. Finding out that these are just myths can provide a lot of relief to clients. This can be sufficient, in some cases, to help them to change the way they think about their symptoms and enable them to interrupt their own vicious cycle. For others, however, more long-standing ingrained beliefs may need more work.
Perfectionistic beliefs are common in IBS. Facilitating the link between these kinds of belief, stress and the bowels can motivate people to consider alternative ways of responding to perfectionistic thinking. As with all CBT, we first provide individuals with the tools for identifying unhelpful thoughts. Categorising thoughts as all-or-nothing or self-critical, can shift automatic tendencies to follow or absorb the thought and instead flag it as an unhelpful habit. As well as challenging thoughts ‘intellectually’, such as by weighing up evidence for and against a particular thought, we facilitate people to challenge beliefs experientially. A perfectionist who finds it hard to switch off and engages in a lot of intense patterns of activity, would be introduced to using relaxation and sleep hygiene. These alternative behavioural strategies can help lessen the intensity of ‘should’ thoughts and ultimately challenge them in themselves.
With a growing understanding of the close link between brain and gut, it may be less surprising that working on thoughts related to gut symptoms reduces symptom severity in IBS. There are current moves to implement the self-management CBT platform in the NHS, and Professors Chalder and Moss-Morris are providing training to therapists within Improving Access to Psychological Therapy in CBT tailored to IBS.
- Drossman, D. A. (1996), ‘Gastrointestinal illness and the biopsychosocial model’, Journal of clinical gastroenterology, 22(4), pp. 252–4.
- Everitt, H. A., Landau, S., O’Reilly, G., Sibelli, A., Hughes, S., Windgassen, S. et al. (2019a), ‘Assessing telephone-delivered cognitive behavioural therapy (CBT) and web-delivered CBT versus treatment as usual in irritable bowel syndrome (ACTIB): a multicentre randomised trial’, Gut: https://gut.bmj.com/content/68/9/1613.
- Everitt, H. A., Landau, S., O’Reilly, G., Sibelli, A., Hughes, S., Windgassen, S. et al. (2019b), ‘Cognitive behavioural therapy for irritable bowel syndrome: 24-month follow-up of participants in the ACTIB randomised trial’, The Lancet Gastroenterology & Hepatology.
- Ford, A. C., Quigley, E. M., Lacy, B. E., Lembo, A. J., Saito, Y. A., Schiller, L. R. et al. (2014), ‘Effect of antidepressants and psychological therapies, including hypnotherapy, in irritable bowel syndrome: systematic review and meta-analysis’, The American journal of gastroenterology, 109(9), p. 1350.
- Kennedy, T., Jones, R., Darnley, S., Seed, P., Wessely, S., and Chalder, T. (2005), ‘Cognitive behaviour therapy in addition to antispasmodic treatment for irritable bowel syndrome in primary care: randomised controlled trial’, BMJ, 331(7514), p. 435.
- Windgassen, S., Moss-Morris, R., Goldsmith, K., & Chalder, T. (2019), ‘Key mechanisms of cognitive behavioural therapy in irritable bowel syndrome: The importance of gastrointestinal related cognitions, behaviours and general anxiety’, Journal of psychosomatic research,118, pp. 73–82.
- Study was funded by the National Institute of Health Research, Health Technology Assessment
- Professor Hazel Everitt, Professor of Primary Care Research at the University of Southampton was the lead investigator of the Assessing Cognitive Therapy in Irritable Bowel Study.
- Professor Rona Moss-Morris and Professor Trudie Chalder of King’s College London, co-developed the CBT programme for IBS delivered in the trial.