Trauma, sepsis, and other conditions of stress are characterized by a hypermetabolic state, in which markedly increased substrate availability is required to meet energy demands for tissue repair and host defenses. Inability to meet these increased metabolic demands results in accelerated visceral protein depletion, impaired immune function, and impaired wound healing. In addition, alteration of the gut flora, impaired host immune defenses, or direct gut mucosal injury may result in gut barrier failure. All of the above derangements, acting in concert, may ultimately lead to sepsis or multiple organ failure. Since enteral nutrition improves resistance to experimentally induced infections, blunts the hypermetabolic response to injury, and maintains intestinal structure and function better than parenteral nutrition, there are many reasons to favor a policy of early enteral feeding in critically ill patients. We demonstrated the safety and efficacy of immediate enteral feeding in patients with major thermal injury, and have found this practice to be applicable to a wide variety of other critically ill patients. These patients had not been felt to be candidates for enteral nutrition due to unfounded fears related to the presence of ileus or fresh gastrointestinal anastomosis.