Steatorrhea

Excerpt

The definition of steatorrhea is an increase in fat excretion in the stools. Steatorrhea is one of the clinical features of fat malabsorption and noted in many conditions such as exocrine pancreatic insufficiency (EPI), celiac disease, and tropical sprue. An increase in the fat content of stools results in the production of pale, large volume, malodorous, loose stools. Screening for steatorrhea may be carried out by examining stool samples for the presence of fat by Sudan III staining. However, quantitative fecal fat estimation is required to confirm the diagnosis.

Among the macronutrients, digestion and absorption of fat involve a complex mechanism. Fat absorption requires bile acids, digestive enzymes, and a normally functioning small intestinal mucosa. Dietary lipids, mostly as triacylglycerols, are initially emulsified by bile acids and then hydrolyzed by the pancreatic lipases and colipases into free fatty acids and monoglycerides. In the proximal small bowel, these hydrolyzed lipids form micelles by the action of bile acids. The micelles are then absorbed across the intestinal villi and transported as chylomicrons via the intestinal lymphatics. Therefore, any defects in the availability or function of bile acids, pancreatic digestive enzymes, or absorptive villi will lead to steatorrhea.