This is a prospective, observational research study for patients with IBD under the care of a gastroenterologist provider. The objective of the Corrona Inflammatory Bowel Diseases (IBD) Registry is to create a national cohort of patients with IBD.The diseases under study include Crohn's Disease (CD), Ulcerative Colitis (UC) and Indeterminate Colitis (IC). Data collected will be used to better characterize the natural history of the disease and to extensively evaluate the effectiveness and safety of medications approved for the treatment of IBD .Approximately 10,000 patients and 150 clinical sites in North America will be recruited to participate with no defined upper limit for either target. The Corrona IBD Registry is a long-term observational study; therefore, the duration of the registry has no pre-determined stop date.