Test Code FATF Fat, Feces
Reporting Name
Fat, FUseful For
Diagnosing fat malabsorption due to pancreatic or intestinal disorders
Monitoring effectiveness of enzyme supplementation in certain malabsorption disorders
This test is not useful for differentiating among pancreatic diseases.
Performing Laboratory
Mayo Clinic Laboratories in RochesterSpecimen Type
FecalNecessary Information
Length of collection period is required.
Specimen Required
Patient Preparation:
1. 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.
2. The use of diaper rash ointments will falsely elevate test results. Discontinue use during collection period.
3. Barium interferes with test procedure; a waiting period of 48 hours before stool collection analysis is recommended.
Supplies: Stool Containers - 24, 48, 72 Hour Kit (T291)
Container/Tube: Stool container complies with shipping requirements, do not use other containers.
Specimen Volume:
Preferred: Entire 48-hour or 72-hour collection
Acceptable: Entire 24-hour or a minimum of 5 g from a random collection
Collection Instructions:
1. All containers must be sent together.
2. The entire collection must contain at least 5 g of feces.
3. For a random collection, a minimum of 5 g (do not send entire collection) is required.
4. The number of containers sent should be indicated on the labels (1 of 4, for example).
Additional Information:
1. Patient can store sample at refrigerate temperature during collection period.
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.
Specimen Minimum Volume
See Specimen Required
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Fecal | Frozen (preferred) | 180 days | |
Refrigerated | 180 days |
Reference Values
TIMED COLLECTION
≥18 years: 2-7 g fat/24 h
Reference values have not been established for patients who are younger than 18 years of age.
RANDOM COLLECTION
All ages: 0-19% fat
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
82710
Clinical Information
Total fecal lipids include glycerides, phospholipids, glycolipids, soaps, sterols, cholesteryl esters, and sphingolipids. Excess fecal fat in feces, (steatorrhea) is indicative of malabsorption disorders, such as pancreatic insufficiency or Whipple disease. Therefore, measurement of the fecal fats can be useful in establishing a diagnosis of such pancreatic diseases as cystic fibrosis, chronic pancreatitis, neoplasia, or stone obstruction and such intestinal diseases as Whipple disease, regional enteritis, tuberculous enteritis, gluten-induced enteropathy (also called celiac disease or sprue), and the atrophy of malnutrition.
Distinguishing free fatty acids from neutral fats, once thought to be helpful in the differential diagnosis of pancreatic disease, has fallen out of favor. Note that the composition of fats in the feces, normally predominately free fatty acids, can change significantly to predominately neutral fatty acids when the patient is on orlistat. This test does not distinguish between free and neutral fatty acids.
Reject Due To
Preservative, media, or charcoal | Reject |
Method Name
Nuclear Magnetic Resonance (NMR) Spectroscopy
Forms
If not ordering electronically, complete, print, and send Gastroenterology and Hepatology Test Request (T728) with the specimen
Day(s) Performed
Monday through Saturday