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HelpTest ID UREDF Reducing Substance, Feces
Specimen Required
Supplies: Stool container, Small (Random), 4 oz Random (T288)
Container/Tube: Fecal container
Specimen Volume: 3 g
Collection Instructions:
1. Collect a loose, unpreserved, random fecal specimen.
2. Freeze immediately.
Additional Information: If additional tests are ordered, aliquot and separate sample prior to freezing to allow 1 container per test.
Forms
If not ordering electronically, complete, print, and send a Gastroenterology and Hepatology Test Request (T728) with the specimen.
Secondary ID
607696Useful For
Assisting in the differentiation between osmotic and nonosmotic diarrhea
Screening test for:
-Diarrhea from disaccharidase deficiencies, (eg, lactase deficiency)
-Monosaccharide malabsorption
Method Name
Benedict's Copper Reduction Reaction
Reporting Name
Reducing Substance, FSpecimen Type
FecalSpecimen Minimum Volume
2 g
Specimen Stability Information
| Specimen Type | Temperature | Time | |
|---|---|---|---|
| Fecal | Frozen | 7 days |
Clinical Information
Fecal reducing substances (carbohydrates) aids in determining the underlying cause of diarrhea. Elevations in fecal reducing substances help distinguish between osmotic diarrhea caused by abnormal excretion of various sugars as opposed to diarrhea caused by viruses and parasites. Increased reducing substances in stool are consistent with, but not diagnostic of, primary or secondary disaccharidase deficiency (primarily lactase deficiency) or intestinal monosaccharide malabsorption. Similar intestinal absorption deficiencies are associated with short bowel syndrome and necrotizing enterocolitis.
Reference Values
Negative or trace
Cautions
This test has poor sensitivity for oligosaccharides.
Antibiotics can alter the intestinal flora and affect acid production.
False-positive reactions due to drugs (salicylates, penicillin, ascorbic acid, nalidixic acid, cephalosporins, and probenecid) are possible.
Feces may be contaminated with urine, in which case glycosuria will give false-positive results.
Diaper collections can be falsely decreased as the fluid portion containing water soluble sugars is absorbed into the diaper.
Bacteria in specimen consumes sugars resulting in falsely decreased values. Specimen should be frozen within 30 minutes of collection.
Day(s) Performed
Monday through Saturday
Report Available
1 to 3 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
84376