A Randomized Waitlist‐Controlled Trial of a Positive Psychology Intervention for Irritable Bowel Syndrome: The WISH Proof‐of‐Concept Trial

Background Though greater positive psychological well‐being (PPWB) is associated with both improved physical and mental health in irritable bowel syndrome (IBS), it has not yet been explored as a primary target of brain–gut behavior therapies (BGBTs). Accordingly, we developed a novel, 9‐week, phone‐delivered BGBT to cultivate PPWB in IBS, and examined its feasibility, acceptability, and preliminary effects in a randomized waitlist‐controlled proof‐of‐concept trial. Methods Twenty‐two adults with IBS meeting Rome IV criteria were randomized, stratified by gender and IBS subtype, to the intervention ( n = 12) or waitlist‐control (WLC; n = 10) groups. Participants completed specific positive psychology (PP) activities and phone sessions weekly with an interventionist. Intervention feasibility was assessed by the proportion of completed sessions, and acceptability by weekly ease/utility ratings. Exploratory psychological and health‐related self‐report measures were collected pre‐ and post‐intervention. Key Results Participants ( N = 22; ages 19–79; 55% female) completed 85% of sessions, above our a priori feasibility threshold of 65%. The intervention was rated as easy to complete (mean = 7.2/10, 95% CI: [6.70, 7.75]) and subjectively helpful (mean = 7.6/10, 95% CI: [7.14, 8.01]). Of the 18 participants who completed the intervention, 11 (61%) no longer met criteria for IBS post‐intervention. Compared to the WLC, the intervention led to promising but nonsignificant improvements in exploratory clinical outcomes including IBS symptom severity, IBS health‐related quality of life, and resilience, with effect sizes ranging from 0.1 to 0.7. Conclusions and Inferences This 9‐week, phone‐delivered intervention targeting greater PPWB in IBS was feasible, well‐accepted, and associated with promising improvements in key IBS‐related outcomes, highlighting the need for further testing.