It is now clear that atrophy of the intestinal mucosa can occur rapidly after injury and that the degree of atrophy is quantitatively related to the severity of injury. Such atrophy can be associated with translocation of bacteria and endotoxin, which can trigger the hypermetabolic response and induce a septic state, which may ultimately lead to multiple system organ failure. Early enteral feeding following trauma can prevent atrophy of the intestinal mucosa and is associated with a decrease in the hypermetabolic response and the incidence of septic complications and diarrhea. Enteral feeding of complete diets can also improve outcome with other forms of intestinal injury such as gamma irradiation or cytotoxic drugs. In contrast, total parenteral nutrition and elemental enteral diets are associated with atrophy of the intestinal mucosa and increased translocation. The addition of glutamine and/or fiber to elemental diets may decrease translocation in some but not all circumstances. It is now clear that enteral nutrition can influence the incidence and severity of translocation, which in turn can potentially reverse or prevent the adverse effects of injury and inflammation in traumatic injury and serious illness. (Journal of Parenteral and Enteral Nutrition14:170S‐174S, 1990)