This registry study will include volunteer pediatric patients: approximately 2,000 pediatric patients with Crohn's Disease who have been treated with infliximab and approximately 2,000 pediatric patients with Crohn's Disease who have received therapies other than infliximab. Approximately 1,000 pediatric patients with Ulcerative Colitis or Indeterminant Colitis will also be enrolled. All patient treatments for IBD will be decided by the treating physicians in consultation with their patients based on usual clinical practice. Patient information will be collected at the time of enrollment and every 6 months for approximately 20 years. Data collection will include disease characteristics, IBD medications, and safety assessments. Patients will also be asked to complete a brief questionnaire describing school and/or work attendance in order to assess quality of life. Some patients may be asked to participate in a substudy that will evaluate blood levels of formation of proteins that may develop after treatment with infliximab. A small amount of additional blood may be taken at the time of a routine blood draw that is part of a patient's routine medical care as determined by a treating physician.

No study agents will be administered in this registry. All patients will receive standard-of-care treatments prescribed by the patient's physician.