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UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: Fecal Reducing Substances

Test Code(s): FRSB / XFRS

CPT Code(s): 84376, 83986

Test Description: Test Component:

pH, sucrose and reducing substances.

Methodology: Clinitest, pH meter

Days Performed: Mon-Fri, dayshift, as workload dictates.

Turnaround Time: Stat: Not available stat.
Routine: 4 days.

Specimen Requirements

Specimen: Loose stool

Collection Instructions: Collect random stool specimen. Freeze immediately.

Collection Container: Preferred: Sterile screw cap container

Collection Volume: Preferred: 5 mL
Pediatrics: 5 mL

Sample Analyzed: Stool water

Volume Required: Preferred: 5 mL
Pediatrics: 5 mL

Specimen Processing: Freeze immediately.

Specimen Transport: Transport specimen to UWHC Core Laboratory (B4/220). Transport frozen specimen on dry ice if coming from outreach location.

Unacceptable Criteria: Specimens not frozen immediately or specimens that are too dry are not acceptable.

Stability: Refrigerated: 36 hours
Frozen: 7 days


Reference Interval:


 Age 0 days and up:  
 pH:  6.0-7.5
 Reducing substances:  negative
 Sucrose:  negative

Additional Information:

This test was developed and its performance characteristics determined by the UWHC Clinical Laboratories.  This test meets the standards for clinical testing.  This test should not be regarded as investigational or for research use.  The US Food and Drug Administration (FDA) has not approved or cleared this test; however, the FDA has determined that such clearance or approval is not necessary.

Reducing Substances, Fecal

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