Abstract
BACKGROUND: Gastrointestinal cancers are among the most recognised oncological diseases in well-developed countries. Tumours located in the digestive tract may cause the fast occurrence of malnutrition. MAIN TEXT: The perioperative period is a special time for systemic metabolism. Thanks to published guidelines, early universal control nutritional status before treatment, patients may have a chance to get suitable nutritional intervention. Although the first line of the intervention-nutritional consultation as well as the fortification of a diet and oral nutritional support (ONS)-is not debatable, in a case of inability of undergoing an oral feeding, the choice of the way of administration in patients before a surgery may represent a serious clinical obstacle. CONCLUSIONS: Although there is broad agreement in the staging, classification, and role of surgery and nutritional status for outcomes of treatment of gastrointestinal cancers, there the way of nutritional intervention in patients with gastrointestinal cancer are still discussed.