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HelpTest Code LAB390 Stool Fat, Qualitative
Clinical System Name
Stool Fat, Qualitative
Synonyms
LAB390
FAT STOOL
Fatty Acid - Stool
Neutral Fat - Stool
Fecal fat
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: Stools sent in diapers, Insufficient Quantity, Age of specimen
Spin: N
Aliquot: N
Storage location: Core 5 Refrigerator
Off-site collection: Send stool refrigerated in a Sterile Screw-Capped Container (No diapers).
Stability
| Specimen Type | Temperature | Time |
|---|---|---|
| Stool | RT |
≤ 1 h |
| Stool | 2-8 C |
≤ 5 d |
| Stool | -20 C or -70 C |
≤ 14 d |
Availability
| STAT | Performed | TAT |
|---|---|---|
| Y | 24/7 | 1 h |
Performing Laboratory
Seattle Children's Laboratory
Department
Department: Core Chemistry
Phone Number: 206-987-2617 (Client Services)
CPT Codes
82705
Methodology
Method: Sudan IV Stain/Microscopic evaluation
Analytical Volume: 1 gram stool
Reference Range
| Normal | |
| Neutral Fat | Absent or Present |
| Fatty Acids | Absent or Present |
Description
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.