In 42 patients with the dumping syndrome. the mucosa of the resected gastric stump was examined histologically. Bioptic materials were obtained by applying fibrobiopsy and aspiration biopsy under roentgenological control. The great majority of the examined demonstrated some or other degree of the glandular atrophy attended by a fall of the secretary function. In spite of a considerable time lapsed since gastric resection the gastric glands remained intact and the secretary function of the stump continued to be normal. According to the authors the severity of the dumping syndrome does not depend on the nature of morphological changes in the gastric stump mucosa. A sizable proportion of the examined patients demonstrated various changes in the motor function of the stump, more often an accelerated evacuation. The listed changes in the morphological-functional condition of the gastric stump were given due consideration in compiling a dietary pattern for patients with the dumping syndrome.