Vedolizumab in Pediatric Ulcerative Colitis- Comparison With Infliximab

Patients meeting the inclusion criteria and not having any of the exclusion criteria will be randomized 1:1 to one of two study arms - intravenous administration of blinded active drug, infliximab or vedolizumab at weeks 0, 2, 6 and 14. Infliximab will be administered at a dose 5mg/kg body weight, and vedolizumab at a dose of 300 mg (body mass \> 40 kg) and 10 mg/kg (body mass \< 40kg).