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Fecal Fat Stain

Item Value
Approval req'd? No
Available Stat? No
Test code P408
Performed by Microbiology
In House Availability Monday-Friday, day shift only
Method Microscopy
Patient Preparation Administration of barium, bismuth, Metamucil, castor oil or mineral within 1 week prior to collection of the specimen is contraindicated.

Patient should not be taking any synthetic fat substitutes (eg. Olestra) or fat blocking nutritional substitutes.

Patient should be on a fat controlled diet with at least 100 g fat per day prior to testing.
Collection Instructions Do not submit stool in preservative. Deliver to laboratory within 24 hours of collection. Refrigerate if not delivered to laboratory within 2 hours of collection.
Container type Sterile container
Amount to Collect 2 g or 2 mL liquid stool

Sample type Stool
Preferred volume 2 g or 2 mL liquid stool

Min. Volume 1 g or 1 mL liquid stool

Processing notes Refrigerate sample. Freeze at -20C if sample must be held >24 hours before testing is performed.
Normal range
Neural fat Not increased
Total fat Not increased
Synonyms fat, qualitative; fecal fat globules; free fat stain; sudan black; stool fat; stool lipids; fecal lipids
Stability 24 hours refrigerated, 72 hours frozen at -20C
Turn around times Same day or next weekday
Additional information In this microscopic screening technique for determining the presence of fat in stool, Sudan IV stain detects the presence of neutral fats and fatty acids. Neutral fats are composed of one or more fatty acids with an alcohol like glycerol. They include the monoglycerides, diglycerides and triglycerides. Fatty acids are carboxylic acids with a long chain of even numbered carbon atoms. They are usually derived from tiglycerides or phospholipids. When they are not attached to other molecules they are known as "free" fatty acids. Results are reported as Neutral Fat and Total Fat, which includes neutral fat and fatty acids.

Increased neutral fat suggests pancreatic enzyme deficiency. Increased total fat with normal neutral fat suggests inadequate absorption or impaired bile secretion.
This is a qualitative method. Confirmation of steatorrhea is best obtained by a quantitative fecal fat analysis (72 hour stool collection).
CPT coding 89125
LOINC code 10753-2
Last Updated 6/13/2016 10:06:40 PM
Entry Number 373
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