Prevalence of Non-alcoholic Fatty Liver Disease in Patients With Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis.

Non-alcoholic fatty liver disease (NAFLD) has emerged as one of the significant comorbidities in patients with inflammatory bowel disease (IBD). This systematic review and meta-analysis aimed to synthesize existing evidence on NAFLD prevalence in IBD patients and explore sources of heterogeneity. A comprehensive literature search was conducted across PubMed/MEDLINE, Embase, Web of Science, and Scopus from January 2016 to September 2025, including studies reporting NAFLD prevalence in adult IBD patients diagnosed through imaging, biopsy, or validated biomarkers. Two independent reviewers screened studies and extracted data on patient demographics, IBD subtypes, and NAFLD diagnostic methods. Quality assessment was performed using the Newcastle-Ottawa Scale. Thirty-five studies encompassing over 47 million IBD patients were included. The pooled prevalence of NAFLD in IBD patients was 26% (95% CI: 23-29%), with substantial heterogeneity (I² = 99.9%). Subgroup analysis revealed a higher prevalence in cross-sectional studies (40.9%) compared to retrospective studies (19.5%). Crohn's disease patients demonstrated higher NAFLD prevalence (26.1%) than ulcerative colitis patients (17.0%). Studies published from 2020 onwards reported a slightly higher prevalence (27.5%) compared to earlier studies (24.8%). The findings indicate that approximately one in four IBD patients has concurrent NAFLD, representing a substantial comorbidity burden. These results underscore the importance of systematic NAFLD screening in IBD patients and integrated multidisciplinary care addressing both gastrointestinal and metabolic complications.