Reducing Substances (Faeces)

Testing Laboratory

Auckland Te Toka Tumai | Auckland Hospital

Department

Chemical Pathology

Delphic Registration Code (Alpha Code)

FRED

Test Code (Numeric Code)

3254

Laboratory Handling

Transport

Freeze the specimen if not analysed within 2 hours of collection.

Registration

FREEZE IMMEDIATELY - Place in Special Techniques box in Specimen Services freezer immediately upon receipt in the laboratory.

Separating

A separate sample is required if other faecal tests have been requested.

Laboratory

LabPLUS Special Techniques

Sample Stability

Must be frozen within 2 hours of collection

Synonyms

Faecal Reducing Substance

Turnaround Time

1 week

4 days/ twice weekly. May be provided urgently upon request (0800 - 1600 weekdays).

Specimen Type

  • Faecal

Specimen Requirements

Tube/Container Type:

Preferred
  • Faeces Container (White Lid)
  • Please refer to Additional Information below

Paediatric Specimen Requirements

Tube/Container Type:

Preferred
  • Faeces Container (White Lid)
  • Please refer to Additional Information below

Pre-testing Requirements

A separate sample is required if other faecal tests have been requested

Additional Specimen Information

SPECIMEN: >1 g faeces

Fresh faecal collect of <2hours is preferable. Avoid contamination (causes false positives). Freeze the specimen if not analysed within 2 hours of collection. A separate sample is required if other faecal tests have been requested. Avoid collecting the sample from absorbent nappies as the reducing sugars in the fluid component of faeces might be disproportionally retained in the nappy. This test will NOT be offered to patients aged 6 years and over. This is due to significant background interference by normally coloured faecal fluid. If there is concern for lactose or fructose malabsorption, consider organising hydrogen and methane breath test (refer to: Breath hydrogen and methane in the LabPlus Test guide).

Last updated: 31/08/2026