A new, totally balanced bulkage-free peptide diet was imposed on 20 patients preparing ror coloscopy. Because of the entire absorption of the oligopeptides by way of the intestinal mucous membrane, the application of this diet brings about the same good results as the administration of the bulkage-free diets containing pure L-aminoacids ("astronaut's nutrients"), which so far were provided for this purpose. Apart from a lower osmolarity and lower costs, the bulkage-free peptide diet offers, above all, the advantages of a definitely better flavor. Therefore, new possibilities for a long-term nutrition with a bulkage-free diet are seen.