Until relatively recently, the gastrointestinal (GI) trakt was considered a dormant, metabolically and immunologically inactive orgán in critically illnesses. However, the GI trakt provides a number of crucial functions that, in fact, may influence morbidity and mortality of many critically ill patients. Its large absorptive area provides a site for nutrient digestion and utilization and serves as an important barrier preventing the systemic absorption of intraluminal microbes and its toxic products. Moreover, the GI trakt is the largest reservou of lymphocytes in the body, which significantly contribute to the immune response of the critically ill patients. The gut dysfunction occurs frequently and early in the intensive care patients. Abnormal colonization, impaired intestinal epithelial barrier function and bacterial translocation represent the key components of gut failure implicating in the pathogenesis of sepsis and multiorgan dysfunction. This review summarizes recent insights finto the role of the gut in critically ill patients with particular focus on 1) the basis of „gut-origin hypothesis", 2) pathophysiology of gut dysfunction, 3) monitoring of intestinal function, and 4) protective measures and novel therapeutic strategies.

        Key words: bacterial translocation, intestinal mucosa, permeability, regional blond flow, selective