COMPARE - Pediatric Inflammatory Bowel Disease (PIBD)

Inclusion Criteria: * Age \< 18 years at study enrollment * Diagnosis of CD, UC, or IBD-U by standard diagnostic criteria * Prior non-response or loss of response to one or more anti-TNF agents * Planning to initiate treatment with any of the following comparator agents: vedolizumab (α4β7 integrin antibody), ustekinumab (anti-IL-12/23 antibody), risankizumab, guselkumab, or mirikizumab, (IL-23 inhibitors), tofacitinib (JAK inhibitor), and upadacitinib (JAK inhibitor). Biosimilars or generic medications for any of the above will also be allowed and handled/analyzed in an identical manner to originators. * Ability to provide child assent, if required per regulatory or local institutional guidelines, and parental informed consent in English or Spanish Exclusion Criteria: * Plans to change care to a different center within 1 year * Prior use of a comparator agent (i.e., only patients starting their first comparator medication as monotherapy following anti-TNF will be eligible) * Contraindication to any of the treatments under investigation * Patients with UC or IBD-U who have undergone colectomy * Patients with current ostomy