Gastrointestinal symptoms and disorders in multiple sclerosis: a systematic review and meta-analysis.

BACKGROUND: Gastrointestinal (GI) symptoms and disorders are frequently reported in multiple sclerosis (MS), but the evidence remains fragmented and highly diverse. We conducted a systematic review and meta-analysis to define the extent and range of GI symptoms and disorders in people with MS (pwMS). METHODS: PubMed, Scopus, and Web of Science were searched from inception through October 1, 2025. Eligible studies included observational and interventional designs that reported GI symptoms or diseases in MS. Random-effects meta-analyses were performed for outcomes reported by three or more studies. Prevalence estimates were pooled across all eligible studies, and odds ratios (ORs) were additionally calculated for outcomes reported in case-control studies. RESULTS: A total of 114 studies involving 1,272,170 pwMS were included. Autonomic GI dysfunction was the predominant phenotype, affecting approximately one-third of pwMS (31.4% [95% CI 26.4-36.5%]), with a high prevalence of dysphagia (43.4% [95% CI 35.9-51.0%]) and bowel dysfunction (37.9% [95% CI 25.0-51.8%]). When analyzed by anatomical domains, lower GI symptoms and disorders were more frequent than upper GI manifestations (28.9% vs 11.5%). In case-control analyses, pwMS had significantly higher odds of autonomic GI dysfunction compared with controls (OR 3.26 [95% CI 1.81-5.86]). Substantial between-study heterogeneity was present across all analyses. CONCLUSIONS: Autonomic GI involvement is a common and clinically important aspect of MS. Marked heterogeneity reflects differences in assessment methods and populations, supporting the view of pooled estimates as general indicators and emphasizing the need for standardized outcome definitions and structured clinical screening.