People sometimes say that they have a “gut feeling” about something. Once this was just a common phrase, but it has now become a popular research focus, especially how altered brain chemistry from behaviour or mood can alter the gut microbiota. The vicious cycle questioning which came first – did anxiety cause irritable bowel syndrome (IBS), did psychological factors cause physical factors, or vice versa. I have come across so many patients who suffer from both conditions and in practice, I have developed more integrated recommendations to help in their management. Emerging evidence has recently demonstrated that there may be a link between IBS with mental health, including anxiety. This article aims to help dietitians in providing holistic management options for both conditions.
Abdominal pain, discomfort, changes in bowel habits (mostly associated with defecation), bloating, diarrhoea, constipation (or a mix of both) are all too common for patients with IBS. This is especially as it can be a chronic, relapsing and often lifelong disorder.1 The British Society of Gastroenterology (BSG) guideline in 2007, was reviewed and updated in April 2021 to reflect the advances in the diagnosis and management of IBS. Irritable bowel syndrome is now described as a disorder in the brain-gut interaction, rather than a functional gastrointestinal disorder.2
This correlates with the rise in mental health disorders, including anxiety and behavioural disturbances from perceived fear.3 Anxiety involves multiple systems within the body and can involve biochemical changes leading to physical changes, such as sweating, increased heart rate, deep breathing and in some cases, gastrointestinal symptoms. There are also multiple causes, giving rise to distinct types of anxiety disorders:
Studies have found that people with IBS are three times more likely to suffer from a mental health condition, such as anxiety.4 Individuals who suffer from both IBS and anxiety report more gastrointestinal symptoms and a reduced quality of life. This could impact on sleep, relationships, or lifestyle choices. Although more research is needed in this specific area, the deliberating IBS and anxiety combination has been exacerbated since the COVID-19 pandemic.5
There has been no association between anxiety and IBS subtypes, increasing the range of sufferers.6 I have found that most patients with IBS can openly recognise they have some degree of psychological influence which may be associated with their physical symptoms. From experience, this ranges diversely from a recent house move increasing short term stress, to studying a degree at university, or on the other end, a diagnosed mental health condition, such as anxiety. All of these can impact on the brain-gut axis in many different ways
Microbial factors have now been shown to impact on the development of IBS symptoms, altering the gut-brain axis.7 This is the bidirectional communication between the enteric nervous system and the central nervous system, and involves such pathways, including endocrine, immune, neural, and metabolic.8 Any dysregulation to the brain-gut microbiome can lead to dysbiosis (altered intestinal microbiota).8 The powerful influence of your brain can influence your gut, and vice versa.
It can be a challenge as a dietitian, trying to help a patient manage both IBS and anxiety. It is encouraged to consider non-dietary management too, to promote a more integrated approach to the management of IBS, which may also alter the brain chemistry and positively impact on anxiety symptoms too. Examples can include:
Most of these non-dietary approaches do not have consistent, strong evidence, but can contribute to a positive lifestyle change (and they do sound appealing!).
In addition to non-dietary management, common diet therapy should be considered:
Anxiety and IBS are both complex conditions and involve numerous psychological and physical interactions. There has been little research on individuals diagnosed with both conditions, and this is an area to focus on going forward.16 Dietary management and non-dietary approaches can help to compliment the management of IBS and anxiety, providing a more inclusive and patient centred approach. A combination of therapies may help to reduce the cost of pharmacological options and promote more exercise and wellbeing options out there for all to enjoy. Encourage self-management where indicated, in addition to diet therapy!
Hannah Pritchard is a UK registered Dietitian, specialising in conditions of the gastrointestinal system. She is particularly interested in IBS, Crohn's disease, Ulcerative colitis and Coeliac disease. Working in the NHS, voluntary and private sectors has enabled her to develop a range of experiences, working with a mixture of people to improve their gut health and achieve their nutrition goals.