tests of carbohydrate malabsorption

Last reviewed 01/2018

Tests of monosaccharide absorption:

  • xylose tolerance test
  • jejunal biopsy

Tests of disaccharide absorption:

  • breath hydrogen test - using lactose or sucrose
  • measurement of plasma glucose following oral dose of lactose or sucrose
  • measurement of disaccharidase activity in jejunal biopsy samples
  • faecal acidity - faecal pH may fall due to bacterial malabsorption of unabsorbed carbohydrate

Radiological studies - intestinal hurry and dilatation may be demonstrated by mixing the appropriate sugar with barium.