This test is performed following a positive screen for Faecal Reducing Substances. Faecal sugar chromatography may aid the diagnosis of classical galactosaemia, sucrose malabsorption, lactose intolerance or fructosuria/hereditary fructose intolerance.
Carbohydrate malabsorption can result from a defect in any part of the digestive or absorption process but it is principally mucosal abnormalities of hydrolysis (e.g. enzyme deficiency) or transport (e.g. damage to villi) that result in clinical disease. A specific diagnosis is aided by thin layer chromatography of faecal extracts which provides both a qualitative and a semi-quantitative picture of the sugars present. e.g. In the disaccharidase deficiency `lactase deficiency’ – lactose, galactose and glucose may be present. In congenital glucose-galactose malabsorption – only glucose and galactose will be present.
Clinical Indications Investigation of carbohydrate absorption is indicated in children who have chronic diarrhoea, and in those who fail to thrive or have persistent diarrhoea following a bout of gastroenteritis.
Reference Range See report
Sample Required Faeces in universal container, Store frozen after receipt in lab.