Person:

Ballou, Sarah

Background: Placebo medications, by definition, are composed of inactive ingredients that have no physiological effect on symptoms. Nonetheless, administration of placebo in randomized controlled trials (RCTs) and in clinical settings has been demonstrated to have significant impact on many physical and psychological complaints. Until recently, conventional wisdom has suggested that patients must believe that placebo pills actually contain (or, at least, might possibly contain) active medication in order to elicit a response to placebo. However, several recent RCTs, including patients with irritable bowel syndrome (IBS), chronic low back pain, and episodic migraine, have demonstrated that individuals receiving open-label placebo (OLP) can still experience symptomatic improvement and benefit from honestly described placebo treatment. Methods and design This paper describes an innovative multidisciplinary trial design (n = 280) that attempts to replicate and expand upon an earlier IBS OLP study. The current study will compare OLP to double-blind placebo (DBP) administration which is made possible by including a nested, double-blind RCT comparing DBP and peppermint oil. The study also examines possible genetic and psychological predictors of OLP and seeks to better understand participants’ experiences with OLP and DBP through a series of extensive interviews with a randomly selected subgroup. Discussion OLP treatment is a novel strategy for ethically harnessing placebo effects. It has potential to re-frame theories of placebo and to influence how physicians can optimize watch-and-wait strategies for common, subjective symptoms. The current study aims to dramatically expand what we know about OLP by comparing, for the first time, OLP and DBP administration. Adopting a unique, multidisciplinary approach, the study also explores genetic, psychological and experiential dimensions of OLP. The paper ends with an extensive discussion of the “culture” of the trial as well as potential mechanisms of OLP and ethical implications. Trial registration ClinicalTrials.gov, identifier: NCT02802241. Registered on 14 June 2016. Electronic supplementary material The online version of this article (doi:10.1186/s13063-017-1964-x) contains supplementary material, which is available to authorized users.

Irritable bowel syndrome (IBS) is a chronic functional disorder of the gastrointestinal tract and is one of the most commonly diagnosed gastrointestinal diseases. The impact of IBS on the general population is large due to its high prevalence, suboptimal medical treatments and significant economic burden. The pathophysiology of IBS is complex and treatments are often symptom-specific. The most common therapeutic approaches for IBS include education and reassurance, lifestyles (especially nutrition-based interventions), peripherally acting medications (which typically target motility), centrally acting medications (which target visceral hypersensitivity and pain) and psychological interventions (which aim to reduce the effects of stress or symptom-specific anxiety). A beneficial dietary approach might include the following measures: a diet low in fermentable oligo-,di- and monosaccharides and polyols (FODMAPs), limitation or exclusion of gas-producing foods and/or lactose and gluten and fiber supplementation in selected cases. New therapeutic agents, namely nutraceutics, are also an interesting option in the management of IBS patients. This paper will focus on available dietary interventions for IBS and will review the evidence for nutrition-based therapies.