Multimodality and differentiated treatment of small-intestinal diseases is to combine methods of etiological action with pathogenetic treatment of the main clinical syndromes: chronic diarrhea, malabsorption syndrome, hypercatabolic exudative enteropathy. Each nosological form should be treated specifically. Pathogenetic treatment involves diet therapy, chemotherapeutic correction of metabolic processes (vitamin administration, recovery of normal protein and lipid metabolism, water and electrolyte balance, anemia), management of chronic diarrhea. Treatment regimens are specified for gluten enteropathies, total variable immunodeficiency, Whipple disease, small-intestinal diverticulosis, Crohn's disease, amyloidoses, intestinal lymphoma and retroperitoneal lymph nodes. Clinical experience justifies the above methods as highly effective.