The mRNA expression of oncostatin M (OSM) in colonic tissue is raised in inflammatory bowel disease (IBD) and is mplicated in anti-TNF treatment resistance. OSM has multiple homeostatic functions with both pathogenic and protective roles. Still, its function in IBD continues to be enigmatic. The aim of this study is to evaluate protein expression of OSM and its receptor-β (OSMR) using immunohistochemical staining, along with the tight junction protein occludin and immune cell marker CD45, to understand the possible mechanisms behind its pathogenic effects in inflammatory process.