This is a post-marketing observational study of patients with Inflammatory Bowel Disease (specifically, Crohn's disease or Ulcerative Colitis) who have been prescribed CT-P13 (infliximab) or Remicade (infliximab) for treatment. CT-P13 (brand names Inflectra and Remsima) is a biosimilar medicine to Remicade, meaning it is a biologic medicine that contains the same active substance as Remicade (infliximab). The key study objectives are as follows:||To characterize the population and drug utilization patterns of patients treated with CT-P13 for Crohn's Disease (CD) or Ulcerative Colitis (UC) in the context of standard of care Remicade|To explore the long-term safety profile of CT-P13 in the treatment of patients with CD or UC in the context of standard of care Remicade|To assess the effectiveness of CT-P13 in the treatment of patients with CD or UC in the context of standard of care Remicade