Crohn Disease (CD) can be broadly defined as an inflammatory disease affecting any part of the GI tract from mouth to anus, though it commonly affects the ileum and colon. Importantly, CD is characterized by the involvement of the entire gut wall, with an anatomical location in any part of the GI tract and a tendency to present complications such as fistulae and strictures. There are several theories as to contributing factors for CD pathogenesis. The complex etiology includes an interplay between genetics, bacteria, and environmental factors.