The TREAT (The Crohn's Therapy, Resource, Evaluation, and Assessment Tool) registry is a prospective, observational, multicenter, long-term registry featuring clinical, economic, and humanistic measures characterizing the treatment of Crohn's disease. The physicians will track treatments and patient outcomes over at least a 5-year period. Physicians are expected to manage patients as they would under normal practice conditions. No predefined schedule of visits or medical procedures are required. Data are collected on a semi-annual basis by physicians documenting assessment of disease severity, medication use, and adverse events. Upon enrollment, patients complete a health assessment questionnaire. As this is an observational study, no study drugs are administered. Through the course of the Registry, analyses will be performed to support submissions to health authorities, and questions of academic interest.