Test ID: FATF
Fat, Feces
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
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 fat malabsorption due to pancreatic or intestinal disorders
Monitoring effectiveness of enzyme supplementation in certain malabsorption disorders
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
Nuclear Magnetic Resonance (NMR) Spectroscopy
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
Fecal Fat
Fecal Fat, 48 Hours
Fecal Fat, Qualitative
Fecal Fat, Quantitative
Fecal Fat, Random
Lipids, Stool
Stool, Fat
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 T291)
Specimen Volume:
Preferred: 48 or 72 hour collection
Acceptable: 24 hour or random collection
Collection Instructions: Timed or Random Collection
1. For a timed collection, the entire collection is required.
a. All containers must be sent together.
b. The entire collection must contain at least 5 g.
2. For a random collection, a minimum of 5 g (do not send entire collection) is required.
3. The number of containers sent should be indicated on the labels (1 of 4, for example).
4. See Stool Collection Information Sheet in Special Instructions.
Additional Information:
1. Timed Collections: Length of collection period is required.
2. A separate order and collection should take place if stool bicarbonate, calcium, chloride, magnesium, osmolality, pH, potassium, sodium, , or any microbiology testing is desired.
3. For 3 days prior to and during the collection period:
a. Patient should be on a fat-controlled diet (100-150 g fat per day).
b. No laxatives (particularly mineral oil and castor oil)
c. No synthetic fat substitutes (eg, Olestra) or fat-blocking nutritional supplements
4. The use of diaper rash ointments will falsely elevate test results. Discontinue use during collection period.
5. Barium interferes with test procedure; a waiting period of 48 hours before stool collection analysis is recommended.
Forms: If not ordering electronically, submit a General Request Form (Supply T239) with the specimen.
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 | NA |
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 (preferred) | 180 days |
| Refrigerated | 180 days |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Fecal lipids include monoglycerides, diglycerides, triglycerides, phospholipids, glycolipids, soaps, sterols, cholesteryl esters, and sphingolipids.
Steatorrhea (increased fecal excretion of fat) may reflect a number of pancreatic or intestinal disorders, including chronic pancreatitis with or without stone obstruction, cystic fibrosis, neoplasia, Whipple disease, regional enteritis, tuberculous enteritis, gluten-induced enteropathy (celiac disease), Giardia-associated enteropathy, sprue, or the atrophy of malnutrition.
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.
TIMED COLLECTION
> or =18 years: 2-7 g fat/24 hours
Reference values have not been established for patients who are <18 years of age.
RANDOM COLLECTION
All ages: 0-19% fat
Interpretation Provides information to assist in interpretation of the test results
Excretion of >7 grams fat/24 hours, when on a diet of 100 to 150 g of fat, is suggestive of a malabsorption defect.
Abnormal results from a random specimen should be confirmed by submission of a timed collection.
Test values for timed fecal fat collections will be reported in terms of g/24 hours; the duration of the collection may be 24, 48, 72, or 96 hours. Test values for random fecal fat collections will be reported in terms of percent fat.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
This test is not useful for differentiating among pancreatic diseases.
Proper patient preparation is critical (see Specimen Required). Failure to adhere to a fat-controlled diet or to exclude other oils or oil substitutes from the diet may make interpretation difficult.
Barium interferes with test procedure; a waiting period of 48 hours before stool collection analysis is recommended.
The use of diaper rash ointments will falsely elevate test results. Discontinue use during collection period.
The use of charcoal as a marker is not recommended. If charcoal is used, please notify the laboratory.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Henderson AR, Rinker AD: Gastric, pancreatic, and intestinal function. In Tietz Textbook of Clinical Chemistry. Third edition. Edited by CA Burtis, ER Ashwood. Philadelphia, WB Saunders Company, 1999, pp 1293-1295
2. Modern Nutrition in Health and Disease.10th edition. Edited by ME Shils, M Shike, AC Ross, et al. Baltimore, MD, Lippincott Williams and Wilkins, 2006, pp 1143-1151,1227-1234
Method Description Describes how the test is performed and provides a method-specific reference
After the well-homogenized stool sample is weighed and dried, it is rolled in Teflon and placed in a nuclear magnetic resonance spectrometer (NMR). The NMR determines the percent of fat in the sample. The percent is then converted to grams fat/24 hours excretion or percent fat of random sample.(Unpublished Mayo method)
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.
82710
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 |
|---|---|---|
| STWT | Total Weight | 30078-0 |
| DUR2 | Duration | 13363-7 |
| PFAT | % Fat | In Process |
| TFAT | Total Fat/24 Hr | 16142-2 |
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