Nutrition and Crohn's disease (CD) are intertwined because of the central role of nutrition in the care of patients with CD, specifically the theories regarding a dietary contribution to pathogenesis and formal studies investigating the primary role of nutrition as therapy for CD. Perhaps one of the most important studies evaluating the role of nutrition therapy and bowel rest in the management of CD was performed by Greenberg and colleagues in 1988. This pivotal study attempted to define the role of bowel rest as an independent variable in the management of hospitalized patients with active CD unresponsive to the traditional medical therapy that was available at the time. As the first randomized controlled trial evaluating nutrition intervention in CD, it showed that bowel rest was not a major factor in achieving remission during nutrition support and did not affect outcome during 1-year follow-up. Although these discouraging findings would be subsequently replicated, the role of enteral and parenteral nutrition therapy would evolve during the following years as a result of insight into CD pathogenesis, the emergence of more effective medical therapies, and improved understanding of the role of nutrition in the care of patients with CD.