The primary reason of this study is to observe current treatment options in participants receiving Vedolizumab, intravenous (IV) or subcutaneous (SC), for IBD in Poland. There is no treatment involved in this study, this is only an observational review of ongoing/initiating treatment data relating to Vedolizumab induction and maintenance treatment for IBD [including Ulcerative Colitis (UC) and Crohn's Disease (CD)].

This is a non-interventional, prospective study of participants with moderately to severely active IBD (UC or CD) who are initiating or currently ongoing induction or maintenance treatment with vedolizumab in the real world setting.

The study will enroll approximately 160 participants: 100 participants with UC and 60 participants with CD. The data will be collected prospectively at the study sites and will be recorded into electronic case report forms (e-CRFs). All the participants will be assigned to a single observational cohort:

•Participants with IBD

This single center study will be conducted in Poland at public hospitals and institutions that treat UC and CD. The overall duration of the study will be at least 24 months. Data will be collected at baseline, every 3 months within the first year and every 6 months within the second year, and at the time of switch, discontinuation and/or at routine follow-up visits.

Inclusion Criteria:

1.Participants with moderately to severely active IBD (UC or CD), initiating or ongoing IV induction treatment with vedolizumab in accordance with the current SmPC and National Drug Program (NDP) at baseline OR IBD participants receiving ongoing/maintenance IV vedolizumab treatment, with the option to switch to SC vedolizumab maintenance treatment.

Exclusion Criteria:

1. Prior history of intolerability, hypersensitivity, or other contraindications (active severe infections such as tuberculosis, sepsis, cytomegalovirus, listeriosis, and opportunistic infections such as Progressive Multifocal Leukoencephalopathy) to vedolizumab therapy as defined in the current SmPC.

2. Current or planned participation in an interventional clinical trial for CD or UC.

3. Cognitive incapacity, unwillingness or language barriers precluding adequate understanding or cooperation.

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Adult participants with moderately to severely active UC or CD receiving vedolizumab treatment in accordance with the approved SmPC and NDP.

Takeda provides access to the de-identified individual participant data (IPD) for eligible studies to aid qualified researchers in addressing legitimate scientific objectives (Takeda's data sharing commitment is available on https://clinicaltrials.takeda.com/takedas-commitment?commitment=5). These IPDs will be provided in a secure research environment following approval of a data sharing request, and under the terms of a data sharing agreement.

IPD from eligible studies will be shared with qualified researchers according to the criteria and process described on https://vivli.org/ourmember/takeda/ For approved requests, the researchers will be provided access to anonymized data (to respect patient privacy in line with applicable laws and regulations) and with information necessary to address the research objectives under the terms of a data sharing agreement.