The dysfunction of intestinal barrier allows the translocation of both endotoxin and whole bacterial organisms. It plays an important role in the development of multiple organ failure (MOF). The mucosa ia one component of this barrier. Trauma, atrophy and the "systemic inflammatory response syndrome" increase gastrointestinal permeability. These abnormalities may contribute to the pathophysiology of sepsis. Malnutrition per se compromises the gut's barrier function. Maintenance of gastrointestinal blood flow may be facilitated by (glutamine-enriched?) enteral diets. The most important conclusions of the majority of controlled trials support the concept of the very early enteral nutrition (within 24 hours after trauma): the outcome of seriously ill patients is improved, the rate of complications and infections is reduced. Gastrointestinal motility disorders may interfere with the initiation and tolerance of early enteral nutrition. They may be managed by prokinetic agents (cisapride, erythromycin) or by bypassing the stomach with a nasoenteric tube.