A multi-center observational study based at referral centers and community hospitals within the US. Patients' blood will be collected at enrollment for testing with PredictSURE IBD™, which will occur at a later date. Patients will be prospectively followed up for 12 months with clinicians treating according to local standard of care, with a step-up or accelerated step-up regimen. Clinicians and patients will be blinded to the biomarker results.

This is a multi-center, observational study of newly diagnosed IBD (CD or UC) patients. The Study aims to assess whether a prognostic biomarker can stratify IBD patients in the US.

Inclusion Criteria:

• Active UC or CD with typical symptoms in conjunction with at least one objective measure of disease activity: elevated CRP, calprotectin, endoscopic evidence.
• Not currently receiving systemic therapy* with steroids, immunomodulators or biologics, and at least 7 days since the last steroid dose.
• Due to be managed using a "step-up" or "accelerated step-up" approach (so will not receive biologics as first line therapy).
• Aged 16-80 years old.

Note, the ideal patients for this study are newly diagnosed patients who are treatment-naïve.

Exclusion Criteria:

• The presence of any of the following will preclude patient inclusion:
• Patients with fistulating peri-anal Crohn's disease or active perianal sepsis.
• Obstructive symptoms and evidence of a fixed stricture on radiology or colonoscopy.
• Patients who are scheduled to start on "top-down" therapy or receive biologics as a first line therapy

The target patient populations are newly diagnosed, active CD or UC in patients who are immunomodulator and anti-TNFα treatment naïve.