Abstract
Malabsorption refers to impaired absorption of nutrients. It can result from congenital defects in the membrane transport systems of the small intestinal epithelium or from acquired defects in the epithelial absorptive surface.
The second condition is maldigestion, which is due to impaired digestion of nutrients within the intestinal lumen or at the terminal digestive site of the brush border membrane of mucosal epithelial cells. Although malabsorption and maldigestion are pathophysiologically different, the processes underlying digestion and absorption are interdependent.
As a result, in clinical practice the term malassimilation has come to denote derangements in both processes. The clinical features and diagnosis of malassimilation will be reviewed here.