Review article: exclude or expose? The paradox of conceptually opposite treatments for irritable bowel syndrome.

BACKGROUND: Irritable bowel syndrome (IBS) is a heterogeneous disorder of gut-brain interaction (DGBI) maintained by interacting biological, psychological, and social processes. Interestingly, there are two contrasting yet evidence-based treatment approaches for reducing IBS symptoms: exclusion diets such as those low in fermentable oligo-, di-, monosaccharides and polyols (FODMAPs) and exposure-based cognitive-behavioural therapy (CBT). Exclusion diets recommend patients avoid foods thought to be symptom-inducing, whereas exposure-based CBT encourages patients to expose themselves to foods. AIMS: To address the paradox of conceptually opposite exclusion diets and exposure-based CBT for IBS. METHODS: In this conceptual review, we describe the rationale, practical implementation, evidence base and strengths and weaknesses of each treatment. We conducted up-to-date literature search concerning the low FODMAP diet and CBT, and performed a secondary analysis of a previously conducted trial to illustrate a key point in our review. RESULTS: The low FODMAP diet has demonstrated efficacy, but problems with adherence, nutritional compromise, and heightened gastrointestinal-specific anxiety raise caution. Exposure-based CBT has demonstrated efficacy with substantial evidence for gastrointestinal-specific anxiety as a key mechanism of action. Mediation analysis also showed that increased FODMAP intake mediated decreased symptom severity in exposure-based CBT. However, there is minimal evidence supporting which treatment "works best for whom" and how these approaches could be best integrated. CONCLUSIONS: Even though exclusion diets and exposure-based CBT are conceptually opposite, they each have proven efficacy. Clinicians should familiarise themselves with both treatments. Further research is needed on predictors, mechanisms and moderators of treatment outcomes.

The lived experience of irritable bowel syndrome: A focus on dietary management.

BACKGROUND: Irritable bowel syndrome (IBS) is a disorder of the gut-brain axis with a prevalence of 3.5% in Australia. The complexity of mechanisms underlying IBS means patients often respond poorly to treatment. There is encouraging evidence for the successful use of dietary strategies for short- and long-term management of IBS. OBJECTIVE: The aim of this narrative review was to explore the lived experience of IBS from the patient perspective with emphasis on dietary involvement and diet management of the condition. DISCUSSION: There are a number of dietary constituents implicated in IBS, and patients' main concerns are the trial-and-error nature of identifying triggers, uncertainty regarding food choices and reduced enjoyment of food. Despite this, dietary modifications are accepted by patients and healthcare professionals (HCPs) as an efficacious management strategy. A meaningful relationship with their HCP can improve patient adherence, treatment success and overall satisfaction for patients.

Therapy of IBS: Is a Low FODMAP Diet the Answer?

Irritable bowel syndrome (IBS) is the most prevalent functional gastrointestinal disorder with a worldwide prevalence of 11%. It is characterized by abdominal pain and altered bowel habits in the absence of underlying unique pathology. The condition is associated with poor quality of life and high use of healthcare resources required for management. The low FODMAP diet (LFD) is a recognized treatment for symptom management of IBS; however, approximately 30% of patients do not respond. The aim of this review was to understand the effectiveness and application of the LFD compared with other dietary and non-dietary interventions. Ten studies were included, eight of which assessed the LFD against other dietary interventions including traditional dietary advice, modified National Institute for Health and Care Excellence guidelines, a high FODMAP diet, gluten-free diet and Mediterranean diet, generalized dietary advice, probiotics, and a sham diet. Two studies compared a LFD to non-diet interventions of gut directed hypnotherapy or yoga. The findings clearly support the LFD as an effective treatment in IBS, and although it highlights the role for microbiota and current psychosocial state, it remains challenging to identify what combination of treatments may be best to ensure a personalized approach and overall higher response rates to IBS therapy.

Use of dietary interventions for functional gastrointestinal disorders.

The role of food in the development of symptoms experienced within functional gastrointestinal disorders (FGIDs) is well recognised. This review aims to describe the evidence base for dietary interventions in the different functional esophageal, duodenal and bowel disorders. Randomised controlled trials are lacking for many of the FGIDs, with the exception of irritable bowel syndrome (IBS). Restricting rapidly fermentable, short-chain carbohydrates (FODMAPs) provides an evidence based dietary approach for the management of symptoms of IBS. Recent evidence shows the upper GI motility response varies between carbohydrates, which gives promise for the potential application of the low FODMAP diet in upper GI disorders. In addition to fine-tuning our FODMAP understanding, other observational data and smaller sized studies create an exciting and optimistic future for dietary management of all FGIDs.