Among inflammatory bowel diseases, Crohn’s disease and ulcerative colitis are of particular importance to gastroenterologists treating both children and adults. Although the etiology of these diseases is still largely unknown, knowledge of their immunopathology is increasing. Typically, proinflammatory cytokine production is abnormal, and particularly in Crohn’s disease, the consequent inflammation is responsive to nutritional intervention or anticytokine therapy. The contributions in this volume focus on nutritional therapy, which is important for both the repletion of associated protein-energy malnutrition and for modulation of the inflammatory response. Highlights include the growing role of enteral nutrition as primary therapy in pediatric practice and investigations into the ideal diet composition, including type of formula (polymeric, protein hydrolysate or amino acid). Furthermore, the pro- and anti-inflammatory effects of omega-6 and omega-3 fatty acids, respectively, and their impact on clinical response receive special attention. This publication offers a wealth of information for gastroenterologists dealing with both adults and children, as well as for clinical and research nutritionists, clinical immunologists and others interested in dietetic therapy.