Test Code NITF Nitrogen, Total, Feces
Performing Laboratory

Specimen Type
FecalShipping Instructions
Send entire stool collection (must contain at least 5 g of feces) frozen on dry ice in Mayo Clinic Laboratories-approved container.
Necessary Information
Length of collection period is required.
Specimen Required
Patient Preparation: Laxatives and enemas should not be used during collection as barium and boric acid interfere with test procedure.
Supplies: Stool Containers - 24, 48, 72 Hour Kit (T291)
Container/Tube: Stool container; complies with shipping requirements, do not use other containers.
Specimen Volume: Entire collection (24, 48, 72, or 96 hours)
Collection Instructions:
1. All containers must be sent together.
2. Entire collection must contain at least 5 g of feces.
3. The number of containers sent should be indicated on the labels (ie, 1 of 4)
Specimen Stability Information: Frozen 3 years
Additional Information: Patient can store sample at refrigerate temperature during collection period.
Specimen Minimum Volume
See Specimen Required
Specimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
Fecal | Frozen (preferred) | |
Ambient | 7 days | |
Refrigerated | 7 days |
Reference Values
<16 years: Not established
≥16 years: 1-2 g/24 hours
CPT Code Information
84999
Clinical Information
Nitrogen is a key component of proteins. Nitrogen balance is the difference between the amount of nitrogen ingested and the amount excreted in the urine and feces. A majority of nitrogen is excreted as urea in the urine; however, fecal nitrogen can account for 30% to 50% of total nitrogen excretion.
A patient who is in negative nitrogen balance is catabolizing muscle protein to meet the metabolic requirements of protein catabolism; therefore, urine and fecal nitrogen concentrations may be increased due to stress, physical trauma, surgery, infections, burns, and 11-oxysteroid or thyroxine use. Testosterone and growth hormone have anabolic effects on protein synthesis and may decrease urine and fecal nitrogen levels.
In the course of chronic progressive pancreatitis, as the pancreas is destroyed, serum amylase and lipase may revert to normal. However, excessive fecal nitrogen levels persist and are used as an indicator of pancreatic atrophy.
Reject Due To
Urine and stool mixed | Reject |
Method Name
Dumas Combustion
Day(s) Performed
Friday