Anti-cytokine antibodies, such as Infliximab (an anti TNF alfa chimeric antibody) and Adalimumab (an anti TNF alfa humanize antibody), have been developed and used in clinical practice for the treatment of patients with Crohn disease (CD). Unfortunately, their efficacy is limited. Based on these concepts, a new drug has been developed for IBD treatment. Vedolizumab (VDZ) is able to recognize the α4β7 heterodimer, and selectively blocks gut lymphocyte trafficking.||The hypothesis of this study is that VDZ therapy may be to halt CD disease progression during time and modifying its natural history, using Lemann Index.