BMC Gastroenterol. 2026 Jul 27;26(1):475. doi: 10.1186/s12876-026-05156-y.
ABSTRACT
BACKGROUND: Inflammatory markers are routinely used in the evaluation of inflammatory bowel disease (IBD). Red blood cell distribution width (RDW) has previously been proposed as a potential biomarker in the evaluation of IBD. This meta-analysis and systematic review challenges the utility of RDW in IBD evaluation.
METHODS: We conducted a systematic review and meta-analysis following PRISMA guidelines. A search strategy was formulated based on Medical Subject Headings (MeSH) terms and other relevant medical terms. A comprehensive search of PubMed, Web of Science, and Scopus was performed up to 4th of September 2025. Data were extracted for identifying the role of RDW in IBD detection and its association with disease activity. Statistical analysis employed a random-effects model, with subgroup analysis performed according to different levels of disease activity.
RESULTS: RDW was significantly elevated in patients suffering from Crohn’s disease (CD) (MD = 2.2, p < 0.001) and ulcerative colitis (UC) (MD = 1.36, p < 0.001) compared to healthy controls. Both diseases showed significantly higher RDW in active disease versus remission (CD: MD = 1.29, p < 0.001; UC: MD = 1.11%, p < 0.001). For differentiating active CD from remission, an RDW cut-off > 14% showed a sensitivity of 0.86 and specificity of 0.78 (AUC = 0.83). RDW levels were also significantly higher in active CD compared to active UC (MD = 0.59, p < 0.005).
CONCLUSION: RDW levels were markedly increased in patients with IBD compared to healthy controls. Furthermore, RDW showed a consistent association with both disease activity and severity. Given its wide availability, low cost, and reliable diagnostic performance, RDW could represent a practical and valuable biomarker for evaluating inflammatory bowel disease.
PMID:42509537 | DOI:10.1186/s12876-026-05156-y
