- Fecal Incontinence
|Review article: exclude or expose? The paradox of conceptually opposite treatments for irritable bowel syndrome
Aliment Pharmacol Ther. 2022 Aug;56(4):592-605. doi: 10.1111/apt.17111.Epub 2022 Jul 1.
1Department of Nutrition, Dietetics and Food, Monash University, Notting Hill, Australia.
2Department of Food, Nutrition and Dietetics, La Trobe University, Melbourne, Australia.
3Center for Neurointestinal Health, Massachusetts General Hospital, Boston, Massachusetts, USA.
4Harvard Medical School, Boston, Massachusetts, USA.
5Research Group Health Psychology, KU Leuven, Leuven, Belgium.
6Research Group Experimental Health Psychology, Maastricht University, Maastricht, The Netherlands.
7Department of Clinical Neuroscience, Division of Psychology, Karolinska Institutet, Stockholm, Sweden.
8Laboratory for Brain-Gut Axis Studies (LaBGAS), Translational Research in Gastrointestinal Disorders (TARGID), Department of Chronic Diseases and Metabolism (CHROMETA), University of Leuven, Leuven, Belgium.
9Leuven Brain Institute, KU Leuven, Leuven, Belgium.
10Cognitive and Affective Neuroscience Lab, Department of Psychological and Brain Sciences, Dartmouth College, Hanover, New Hampshire, USA.
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.