The benefits of maintaining and stimulating gastrointestinal function in critically ill patients have led to a growing interest in the use of enteral nutrition in the critically ill, reversing a pattern of high use of parenteral nutrition in intensive care units in the last decade. In the past year, many studies have documented the importance of 'early' (<24 hours of admission) enteral nutrition support. Endoscopic placement of post-pyloric nasoenteric feeding tubes is being used more frequently to establish early reliable enteral access and thereby allow early initiation of enteral nutrition in intensive care unit patients. Additional studies have determined that the provision of specialized enteral nutrition or 'immunonutrition' (supplemented with arginine, glutamine, ribonucleotides and omega-3 fatty acids) is associated with a significant reduction in the risk of developing infectious complications and reduces the overall hospital stay in specific groups of patients with critical illness. These data clearly have important implications for the management of nutritional support in critically ill patients. (C) 2000 Lippincott Williams and Wilkins, Inc.