Background: Obtaining high-quality evidence for efficacy of gut-directed hypnotherapy (GDH) in patients with irritable bowel syndrome (IBS) is constrained by difficulty in designing a blinded placebo. An alternative is to compare GDH to a therapy with proven efficacy, such as the low FODMAP diet (LFD), which benefited 70% of such patients in a recent randomised, controlled trial.1
Aims & Methods: This study aims to determine if GDH is non-inferior in efficacy to the LFD and to assess whether they have additive effects. A randomised controlled trial was performed in IBS patients (Rome-III) comparing (a) LFD: education at the beginning of week 1, review at week 6; (b) GDH: six weekly one-hour hypnosis sessions for 6 weeks; (c) a combination of both. The primary endpoint was the change in overall gastrointestinal (GI) symptoms as evaluated using a 100 mm visual-analogue-scale (VAS) from baseline to week 6. Secondary end-points were the change overall GI symptoms from baseline to 6-months post-treatment and the change in individual gastrointestinal symptoms (abdominal pain, bloating, wind, satisfaction with stool consistency and nausea), psychological indices including anxiety and depression as assessed by the Hospital Anxiety and Depression Scale and IBS-related quality of life (IBS-QOL) from baseline to week 6 and 6-months post-treatment.
Results: Of 74 participants (mean age 40, SD 14 y; 14 male), 25 received the GDH, 24 the LFD and 25 combination therapy. The groups were well matched. Overall GI symptoms improved from baseline to week 6 by a mean [95% CI] of 33 [25, 41], 30 [19, 42] and 36 [27, 45] mm, respectively (all p<.0001) with no differences across the groups (p=.67; one-way-between-groups ANOVA). Improvement (≥ 20 mm reduction) was achieved in 72% who received GDH, 71% the LFD and 72% the combined treatment. Overall symptoms remained improved from baseline to 6-months by 38 [27, 50], 30 [16, 43] and 27 [14, 40] mm (p<.0001). 74% receiving GDH, 82% the LFD and 54% the combined treatment maintained their response. Significant reductions in abdominal pain, bloating, wind and stool consistency, but not nausea were observed from baseline to week 6 and 6-months. No differences in improvement were observed for individual GI symptoms across treatment groups at either time-point. Long-term improvement for HADS anxiety (M=-3.4) and depression (M=-2.16) was only observed in those who received GDH (both p<.0001). IBS-QOL significantly improved in all treatment groups from baseline to week 6 but was only maintained 6-months post-treatment for those who received the combined treatment (all p<.001). No difference in any psychological index was observed across treatment groups from baseline to week 6 or 6-months post-treatment.
Conclusions: Efficacy of GDH is not inferior to that of LFD for relief of GI symptoms in IBS patients, but they do not show additive effects. Long-term improvement in anxiety and depression was superior following GDH. GDH is an effective alternative to the LFD, but the lack of additive effect is unexplained.