 The purpose of this study is to compare changes in protein and lipid metabolism, as well as resting energy expenditure, before and after therapy with anti-TNF-alpha antibody infliximab or corticosteroids in children with recurrent Crohns disease. Performing this study will better define the changes in nutrition status observed in these children following remission of active Crohns disease, and potentially lead to changes in medical and nutritional management of these children. 