Atopic biologic use and recalled irritable bowel syndrome symptom severity: A hypothesis generating retrospective survey evaluation

Background: Case reports indicate that omalizumab may be therapeutic in patients with irritable bowel syndrome (IBS), but this has not been confirmed with follow-up studies. Objective: The present study sought to determine if biologics used to treat atopy have any effect on recalled IBS severity. Methods: All patients ≥ 12 years of age with IBS and currently taking an atopic biologic were sent a questionnaire that assesses IBS severity currently and before starting their atopic biologic. The IBS Symptom Severity Score (IBS-SSS) and IBS Adequate Relief metric were used to quantify IBS severity pre- and post-atopic biologic. Bonferroni-corrected Wilcoxon signed rank tests with Hodges-Lehman estimated median differences and 95% confidence intervals (CI) compared IBS-SSS pre- and post-atopic biologic start. Subset analyses of patients taking omalizumab or dupliumab were also conducted. Results: Sixteen patients (12% response rate) fully responded to the questionnaire (omalizumab, n = 7; dupilumab, n = 7; mepolizumab, n = 1; tezepelumab, n = 1). The majority were women (75%) with a median (range) age of 41 years (22-71 years). The frequency of respondents who reported adequate relief of their IBS did not differ pre- and post-atopic biologic start (p = 0.688), but patients reported significantly decreased IBS-SSS post-atopic biologic start (estimated median difference 70.0 [95% CI, 20.0-122.5]; z = -2.59, p = 0.0097). One patient (6%) taking omalizumab reported complete resolution of IBS symptoms. The majority of the patients (56%) reported a decrease of at least 50 in the IBS-SSS. Although subset analyses of patients taking omalizumab or dupilumab did not show statistically significant differences pre- and post-atopic biologic start, the estimated median IBS-SSS difference pre- and post-atopic biologic start was 93.8 (95% CI, -15.5 to 201.5) and 22.0 (95% CI, -27.5 to 149.0) for omalizumab and dupilumab, respectively. Conclusion: The patients with IBS reported improved recalled IBS severity after starting an atopic biologic, with patients taking omalizumab reporting a larger difference. Future controlled studies are needed to confirm this finding.