Orthostatic Intolerance in Patients With Disorders of Gut-Brain Interaction: A Systematic Review and Meta-Analysis.

BACKGROUND: Patients with severe manifestations of disorders of gut-brain interaction (DGBI) have higher rates of concomitant Orthostatic Intolerance (OI) and Postural Orthostatic Tachycardia Syndrome (POTS). These conditions diminish quality of life and increase health care use. We conducted a systematic review to assess OI and POTS prevalence in patients with DGBI. METHODS: Databases were searched through January 2026 for articles reporting the prevalence of OI and POTS among patients with DGBI. Pooled prevalence rates, odds ratios (ORs), and confidence intervals (CIs) were calculated using a random-effects model. KEY RESULTS: Thirteen studies included 869 patients with DGBI and 1951 controls. OI prevalence in DGBI patients was DGBI (PP=50.0%, 95% CI: 35.0-64.9). The odds of OI in patients with DGBI were significantly higher compared with controls (OR=5.17, 95% CI: 1.73-15.50, P=0.003). Pediatric patients with DGBI had a higher prevalence of OI (59.7%, 95% CI: 36.4-79.3) than adults (32.5%, 95% CI: 19.3-49.4). The prevalence of OI in patients with DGBI was significantly higher when diagnosed using the Rome IV criteria (66.1%, 95% CI: 43.3-83.3) compared with the Rome III criteria (30.6%, 95% CI: 21.4-41.6). The prevalence of OI in DGBI was higher with questionnaire-based diagnosis (54.5%, 95% CI: 9.7-93.0) compared with physician-based diagnosis (48.8%, 95% CI: 35.2-62.7). Finally, POTS was prevalent in 31.5% (95% CI: 17.3-50.2) of patients with DGBI. CONCLUSIONS: OI is more prevalent in patients with DGBI as compared with controls without DGBI. POTS occurs in over one-third of patients with DGBI. While OI and DGBI are associated, clinical heterogeneity suggests low-quality evidence, warranting cautious interpretation.