Mindfulness-Based Stress Reduction for the Treatment of Irritable Bowel Syndrome Symptoms: A Randomized Wait-list Controlled Trial

Irritable bowel syndrome (IBS) is a functional disorder of the lower gastrointestinal (GI) tract affected by stress, which
may benefit from a biopsychosocial treatment approach such as mindfulness-based stress reduction (MBSR).

A treatment as usual (TAU) wait-list controlled trial was conducted in Calgary, Canada to investigate the impact of MBSR on
IBS symptoms. It was hypothesized that MBSR patients would experience greater reduction in overall IBS symptom severity and
self-reported symptoms of stress relative to control patients.

Ninety patients diagnosed with IBS using the Rome III criteria were randomized to either an immediate MBSR program (n = 43) or to wait for the next available program (n = 47). Patients completed IBS symptom severity, stress, mood, quality of life (QOL), and spirituality scales pre- and post-intervention
or waiting period and at 6-month follow-up. Intent-to-treat linear mixed model analyses for repeated measures were conducted,
followed by completers analyses.

While both groups exhibited a decrease in IBS symptom severity scores over time, the improvement in the MBSR group was greater
than the controls and was clinically meaningful, with symptom severity decreasing from constantly to occasionally present.
Pre- to post-intervention dropout rates of 44 and 23 % for the MBSR and control groups, respectively, were observed. At 6-month
follow-up, the MBSR group maintained a clinically meaningful improvement in overall IBS symptoms compared to the wait-list
group, who also improved marginally, resulting in no statistically significant differences between groups at follow-up. Improvements
in overall mood, QOL, and spirituality were observed for both groups over time.

The results of this trial provide preliminary evidence for the feasibility and efficacy of a mindfulness intervention for
the reduction of IBS symptom severity and symptoms of stress and the maintenance of these improvements at 6 months post-intervention.
Attention and self-monitoring and/or anticipation of MBSR participation may account for smaller improvements observed in TAU
patients.