Epidemiology

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Etiology

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Subtypes and variants

Exocrine pancreatic insufficiency

• See Steatorrhea

Short bowel syndrome

• Definition: a condition in which the small bowel cannot adequately absorb nutrients, water, or electrolytes
• Etiology
  • Small bowel resection, e.g., in Crohn disease, trauma
  • Congenital visceral malformations
• Management
  • Diet optimization
  • Total parenteral nutrition in patients with intestinal failure

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Clinical features

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Diagnostics

• Blood tests: macrocytic and/or microcytic anemia; ↓ electrolytes, ↓ total protein, vitamin deficiencies
• D-xylose absorption test: assesses the absorptive function of the upper small intestine
  • Because absorption of D-xylose in the intestine does not rely on the breakdown by pancreatic enzymes, a normal increase in urinary D-xylose excretion indicates a healthy intestinal mucosa. In conditions associated with damage to the intestinal mucosa, oral administration of D-xylose will result in increased fecal D-xylose excretion.
  • Polysaccharides need to be degraded by amylase before absorption. However, monosaccharides (eg, glucose, galactose, D-xylose) are taken up directly by the epithelial cells of the small intestine through either sodium-dependent cotransport or facilitated diffusion.
• Hydrogen breath test: assess the intestinal absorption of individual carbohydrates
• Further testing (for underlying diseases): e.g., celiac disease or lactose intolerance

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Treatment

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