Corticosteroids With Vedolizumab in Crohn's Disease

Inclusion Criteria: * Age at entry 18 to 70 * CDAI score \> 220 * Concomitant azathioprine, methotrexate, or mercaptopurine permitted if dose has been stable for \> 8 weeks. Prior anti-TNFα antibody use permitted but must be discontinued (\>2 weeks from last dose) prior to initiation of vedolizumab. * Documented ulceration on colonoscopy done at screening of 3 or more large ulcers or 10 or more aphthous ulcers * Able to provide written informed consent. * Patient is planned for or eligible to initiate vedolizumab Exclusion Criteria: * Concurrent use of anti-TNFα antibodies. * No corticosteroids within prior 3 months (other than budesonide controlled ileal release) * No stoma at the time of enrollment * No absolute contraindication to systemic corticosteroid use such as hypersensitivity to any part of the formulation, systemic fungal infection, or recent administration of live or live attenuated vaccine within prior two weeks. * Pregnant women or plans for pregnancy within 3 months of study inclusion * Presence of stoma, more than three small-bowel resections, or documented history of short bowel syndrome * Intestinal stricture requiring surgery * Abdominal abscess * Inability or unwillingness to provide informed consent * Any other condition, which, in the opinion of the investigators would impede competence or compliance or possibly hinder completion of the study