Reducing substances (faecal)
| Category | Biochemistry >> Metabolic |
|---|---|
| Test background |
Faecal reducing sugars in infants reflect a process of 'intestinal hurry' or diarrhoea secondary to other causes that prevent complete absorption in the intestines. The main substances likely to be detected in the faeces of infants include: glucose, fructose (fructosuria/intolerance), galactose (galactosaemia) and lactose (lactose intolerance). The reducing sugars assay typically aids initial diagnosis of an inborn error of metabolism. A positive screen for reducing substances in the faeces should be followed by sugar chromatography to identify specific carbohydrates present and provide a quantitative estimation. |
| Clinical Indications |
Neonatal/infantile presentation of generalised failure to thrive, chronic diarrhoea, hepatic dysfunction and developmental delay (often global). |
| Reference range | See report |
| Sample & container required | Faeces in universal container. Store frozen after receipt in lab. |
| Sample volume | 5 g |
| Transport storage | Transport samples to laboratory immediately. Samples from outside NWLP should be sent frozen. |
| Turnaround time | 1 week |
| Notes | A positive screen for faecal reducing substances should be followed by sugar chromatography to identify specific carbohydrates present and provide a qualitative estimation. |