Exclusive Enteral Nutrition (EEN) is the liquid diet given to children with active Crohn's Disease (CD). EEN has previously been shown to induce changes in major bacterial metabolites and dominant bacterial species which are more profound in children that clinically improve. This study aims to determine whether it is possible to maintain these bacterial changes with prolonged supplementary enteral nutrition (SEN) while returning to normal diet and if this can reduce risk of subsequent relapse for children with CD.