International Journal of Preventive Medicine (Int J Prev Med)2008-78021462023073028352835ENStudent Research Committee, Mashhad University of Medical Sciences, MashhadDepartment of Neurology, University of Medical Sciences, GorganMultiple Sclerosis Research Center, Neuroscience Institute, Tehran University of Medical Sciences, TehranUniversal Council of Epidemiology (UCE), Universal Scientific Education and Research Network (USERN), Tehran University of Medical Sciences, TehranMultiple Sclerosis Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran20230722<p>Background: This systematic review and meta‑analysis aim to update the pooled prevalence of Inflammatory bowel disease (IBD) in patients with multiple sclerosis (MS). Methods: Two researchers independently and systematically searched PubMed, Scopus, EMBASE, Web of Science, and google scholar. They also searched for references of the included studies, and conference abstracts that were published up to September 2021. Results: The literature search revealed 5719 articles, after deleting duplicates 3616 remained. Finally, 17 studies were included. The pooled prevalence of IBD in MS was 1% (I2 = 96.3%, P &lt; 0.001). The pooled odds ratio of developing IBD in MS cases was 1.36 (95% CI: 1.1–1.6) (I2 = 58.3, P = 0.01). Conclusions: The results of this systematic review and meta‑analysis show that the pooled prevalence of IBD in MS patients was 1% and the pooled odds ratio of developing IBD in MS cases was 1.36.</p><p> </p>http://ijpm.mui.ac.ir/index.php/ijpm/article/view/2835http://ijpm.mui.ac.ir/index.php/ijpm/article/download/2835/717718701