- Anti-integrin agents (natalizumab, Vedolizumab) If patients meet entry criteria will undergo a baseline endoscopy, colonoscopy and MR or CT enterography. If documentation of active mucosal disease patients will then be tapered off of current medications and undergo stem cell mobilization. Mobilization will involve low dose chemotherapy, growth factors and require 1-2 week hospitalization. Patients will then undergo stem cell transplant which will involve high dose chemotherapy and require a 2-4 week hospitalization. After restoration of the immune system patients will be placed on vedolizumab per standard dosing (0,2,6 then every weeks). Patients will have monthly study visits and a repeat colonoscopy and MR/CT scan at 6 months.