1. A composition containing polysaccharides from cladodium Opuntia Ficus Indica and another active substance which is intended for the prevention and treatment of diseases of the upper gastrointestinal tract, wherein said active substance is selected from omeprazole, lansoprazole, cimetidine, ranitidine, metoclopramide, domperidone, levosulpiride magnesium and aluminum hydroxide, sodium bicarbonate, alginic acid or alginates, chitosan, sucralfate, anti-inflammatory flavonoid extracted from Olea Europeae or Capparis Spinosa, anthocyanoside from red oranges or black rice and these diseases are selected from gastroesophageal reflux, GERD, dyspepsia, gastrointestinal disturbances, pharyngitis, Barrett's esophagus, esophageal adenocarcinoma, GERD-associated lung lesions. 2. The composition according to claim 1, wherein said cladode polysaccharides are in the form of mucus, cladode juice or an aqueous solution of (ultra) filtered cladode juice, which is optionally concentrated and dried. The composition according to claim 1, wherein said cladodium polysaccharides are present in amounts of from 0.5% to 50% based on the weight of the composition. The composition according to claim 1, wherein said active substance belongs to one of the following therapeutic classes: proton pump inhibitors (PPI), H receptor antagonists, prokinetic agents, antacids, cytoprotective agents, anti-inflammatory drugs. The composition according to claim 4, wherein said active substance is selected from omeprazole, lansoprazole, cimetidine, ranitidine, metoclopramide, domperidone, levosulpiride, magnesium and aluminum hydroxide, n�1. Композиция, содержащая полисахариды из кладодия Opuntia Ficus Indica и другое активное вещество, которая предназначена для предупреждения и лечения заболеваний верхнего отдела желудочно-кишечного тракта, при этом указанное активное вещество выбрано из омепразола, ланзопразола, циметидина, ранитидина, метоклопрамида, домперидона, левосульпирида, гидроксида магния и алюмин
