Nutritional aspects of malabsorption. Short gut adaptation.

Adaptation of remaining small bowel after extensive intestinal resection plays an important part in maintaining adequate nutrition. The metabolic consequences of short bowel depend upon the anatomic extent of bowel removed, the functional condition of remaining digestive organs and the degree to which adaptive changes occur. The pathophysiology of short bowel results primarily from the abnormal absorption of nutrients and selective metabolites leading to malnutrition and other organ complications. Nutrients in the lumen of the small intestine are required to stimulate the process of intestinal adaptation (mucosal hyperplasia). This stimulation may be mediated via direct mucosal absorption or metabolism of nutrients, the presence of pancreaticobiliary secretions in the intestine, trophic effects of circulating enteric hormones, or neurovascular influences. Understanding the mechanisms by which mucosal growth may be stimulated could lead to important clinical applications.