Postmarketing Safety Surveillance European Registry of Crohn's Disease Patients Treated With Remicade or Standard Therapy (MK-2155-035)

Inclusion Criteria: * At least 18 years of age, of either sex, and of any race. * Must have active or fistulizing CD and must have experienced at least 1 of the following: * failed a tapering regimen of corticosteroids and will be initiating immunosuppressive therapy * required corticosteroid treatments for the previous 6 months and will be initiating immunosuppressive therapy * luminal or fistulizing CD, which, in the treating physician's judgment, qualifies for initiation of Remicade. * Willing to give written informed consent and must be able to adhere to the procedural requirements of the registry. * Must be evaluated for active and inactive (latent) tuberculosis (TB) at the Baseline Visit. TB evaluation will consist of TB history questions (eg, medical history, possible previous contact with TB, TB vaccination history). TB evaluation and TB screening (eg, skin test, chest x-ray) are required when a subject starts treatment with Remicade. In these cases, subjects must be screened for TB within 3 months prior to initiating Remicade treatment. Exclusion Criteria: * Female who is pregnant or nursing. * Treated with Remicade prior to Baseline. * Previously treated with other tumor necrosis factor (TNF)-active agents and other investigational drugs for CD prior to Baseline. * Active or untreated latent TB or other severe infections such as sepsis, abscesses, or opportunistic infections. * Moderate or severe heart failure (New York Heart Association \[NYHA\] Class III: subjects with marked limitation of activity; they are comfortable only at rest/Class IV: subjects who should be at complete rest, confined to bed or chair; any physical activity brings on discomfort and symptoms occur at rest). * Have lymphoproliferative disorders (eg, lymphoma) or malignancies. * In a situation or have any condition that, in the opinion of the treating physician, may interfere with their optimal participation in the registry. * Are participating in any other clinical trials (excluding registries). In addition, subjects will be excluded from treatment with Remicade if any of the criteria listed below are met: * Females of childbearing potential unwilling to use a medically accepted method of birth control during treatment with Remicade and to continue its use for at least 6 months after the last Remicade treatment. * History of hypersensitivity to murine proteins or to any excipients of Remicade formulation (sucrose, polysorbate 80, monobasic sodium phosphate, and dibasic sodium phosphate). * Other conditions that are contraindicated in the Remicade Summary of Product Characteristics (SPC).