This is a multi-center prospective cohort study in which the investigators are aim to enroll 140 children under the age of 18 years, diagnosed with CD, inflammatory bowel disease unclassified (IBDU) or UC (approximately 70 in UC/IBDU and 70 in the CD group) who commenced on Vedolizumab for any reason at the discretion of the treating physician.
Patients will be followed up to 3 years at 8 different time points: week 0, week 2, week 6, week 14, week 30, week 54 (1 year), week 108 (2 years) and week 162 (3 years). Blood work will be collected at each visit during the time of venous access insertion for the drug infusion for serum and stool sample will be collected at visits 0, 14, 30, and 54. In addition, at week 0 and 14 whole blood will be collected into a PaxGene tube for gene expression analysis.
