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Test Code FAT STOOL Stool Fat, Qualitative

Clinical System Name

Stool Fat, Qualitative


Fatty Acid - Stool
Neutral Fat - Stool
Fecal fat


The normal fat content of feces consists primarily of fatty acids, fatty acid salts (soaps) and neutral fats (triglyceride). A crude technique for estimating stool fat involves staining a stool sample with Sudan IV stain and observing the specimen for neutral fat droplets. If neutral fats are normal, a portion of the specimen is hydrolyzed, stained and observed for fat droplets representing fatty acids. In pediatric patients,this procedure is useful identifying patients who have steatorrhea.

Sample Requirements

Specimen:  Stool

Container(s): Sterile Screw-Capped Container (No diapers).

Preferred Vol: 1 gram stool

Minimum Vol: 1 gram stool


Note: Test includes Neutral Fat and Fatty Acid determinations. Stool samples submitted in diapers are unacceptable. The presence of large amounts of neutral fat may indicate that the patient has had an oily laxative. Qualitative results in children less than 3 months of age may or may not correlate well with quantitative results for stool fat.



Processing Instructions

Reject due to: Insufficient quantity of stool, stools sent in diapers.

Spin: N

Aliquot: N

Temp: 2-8oC

Storage location: Core 5 Chemistry Refrigerator


Off-site collection: Send stool refrigerated in a Sterile Screw-Capped Container (No diapers).



Specimen Type Temperature Time
Stool RT

1 H

Stool 2-8oC

 5 D

Stool -20oC or -70oC

14 D



STAT Performed TAT
Y 24/7 1 H


Performing Laboratory

Seattle Children's Laboratory    


Department:  Core Chemistry

Phone Number206-987-2617

Reference Range


Neutral Fat Absent or Present
Fatty Acids Absent or Present



Method: Sudan IV Stain/Microscopic evaluation

Analytical Volume: 1.0 mL

CPT Codes