Drug-induced inflammatory bowel disease (IBD) is a clinical entity on the rise due to the frequent use of immunomodulatory therapy. Here we report the case of Crohn's disease due to Ocrelizumab, a humanized anti-CD20 monoclonal antibody approved for the treatment of multiple sclerosis. The exact mechanism by which anti-CD20 antibodies can trigger IBD is unknown, but since IBD and multiple sclerosis are processes included within the spectrum of immunomediated diseases, we could suggest that Ocrelizumab could trigger IBD in genetically predisposed patients.