Faecal Reducing Substances

Chemical Pathology

Notes

Sugars (e.g, glucose, galactose, fructose, maltose, lactose, and pentose) are characterized as reducing substances based on their ability to reduce cupric ions to cuprous ions.

Faecal reducing substances have previously been requested when carbohydrate malabsorption is suspected in a child (e.g. evidence of diarrhoea or intestinal hurry not explained by other causes) and to investigate for disaccharidase deficiency.

Analysis of faecal reducing substances has however been withdrawn.

This is because the methods used for analysis of faecal reducing substances are unreliable and no longer recommended for use in the diagnosis of lactose intolerance.

The NICE guideline CG116 Food Allergy in Children and Young People recommends a lactose elimination diet for the diagnosis of lactose intolerance.

Further Information

NICE CG116 Food Allergy in children and Young People

National Metabolic Biochemistry Network

Page last updated 09/07/2015