Test ID: UREDF
Reducing Substance, Feces
NY State Approved 
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Diagnosing intestinal malabsorption in children
Assisting in the differentiation between osmotic and nonosmotic diarrhea
Screening test for:
-Diarrhea from disaccharidase deficiencies, (eg, lactase deficiency)
-Monosaccharide malabsorption
Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test
Method Name A short description of the method used to perform the test
Clinitest Reagent Tablets
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Container/Tube: Stool container (Supply T288)
Specimen Volume: 3 g
Collection Instructions:
1. Collect a loose, random stool collection.
2. See Stool Collection Information Sheet in Special Instructions.
3. If collecting from an infant, use nonabsorbent diapers to collect the specimen. If stool is collected in a disposable diaper, the solid and liquid stool must be combined. The liquid portion of the stool can be aspirated from the diaper using a syringe or alternatively can be expressed from the diaper into a cup. If a diaper has gel absorption, a cotton ball will be necessary to collect the liquid portion of the stool.
4. It is critical that urine is not also mixed with the specimen. Urine will interfere with the results.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | NA |
| Lipemia | NA |
| Icterus | NA |
| Other | Specimens from timed collection (24, 48, 72 hour) or formed stool |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Fecal | Frozen | 7 days |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Sugars (eg, glucose, galactose, fructose, maltose, lactose, and pentose) are characterized as reducing substances based on their ability to reduce cupric ions to cuprous ions.
Fecal reducing substances may be increased in carbohydrate malabsorption syndromes.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Negative or trace
Interpretation Provides information to assist in interpretation of the test results
Negative: negative
Normal: <0.25 g/dL (trace)
Suspicious: 0.25 to 0.50 g/dL (grade 1)
Abnormal: >0.50 g/dL (grade 2-4)
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
A number of other compounds also are capable of reducing cupric ions to cuprous ions and can cause false-positives.
Ambient transport temperatures result in growth of bacteria. Bacteria consume reducing substances, which can result in false-negative results, so ambient specimens are rejected.
This test has poor sensitivity for oligosaccharides and poor sensitivity from diaper stools because fluid is reabsorbed into the diaper. Testing of only the solid portion of the stool will give a falsely-low reading since the liquid portion of the stool contains the water-soluble sugars.
Possible interferences include: salicylates, penicillin, choral hydrate, menthol, phenol, streptomycin, para-aminosalicylic acid, isoniazid, ascorbic acid, cephalosporins, and probenecid.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
Todd S: Archives of disease in childhood: differentiation of osmotic and secretory diarrhea by stool carbohydrate and osmolar measurements. In Clinical Diagnosis and Management by Laboratory Methods. Vol 77. 20th edition. Edited by JB Henry, FR Davey, CJ Herman, et al. Philadelphia, Saunders, 2001, pp 201-205
Method Description Describes how the test is performed and provides a method-specific reference
The Clinitest tablet contains cupric sulfate, citric acid, sodium bicarbonate, and anhydrous sodium hydroxide. The test is a qualitative, nonspecific test for the presence of reducing substances in stool. This test utilizes the ability of sugars to reduce cupric to cuprous ions in the presence of heat and alkali, causing a color change from blue to green to orange depending on the amount of reducing substance present.(Package insert: Bayer Clinitest Reagent Tablets. Bayer Corporation, Elkhart, IN)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
84376
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
| Result ID | Reporting Name | LOINC Code |
|---|---|---|
| 6215 | Reducing Substance, F | 11060-1 |
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