5
Advantages Limitations
Easy—requires only one small stool
sample.
Positive result is unable to inform the
extent of malabsorption.
Negative result does not rule out
malabsorption.
Does not identify cause of fat
malabsorption.
Patient needs to ingest at least 60 g fat/
day.
Demonstrates extent of malabsorption,
comparing fat intake vs. output.
Can demonstrate adequacy of therapy
for patients already on pancreatic enzyme
replacement therapy (PERT) or semi-
elemental EN.
Cumbersome, requiring accurate diet
record and stool collection from 1–3 days.
Does not distinguish between causes of fat
malabsorption.
Patients need to be ingesting enough fat
(ideally 100 g fat/day), but at least 50 g/
day minimum.
Easy—requires a small stool sample.
Do not have to stop PERT for test (only
when monoclonal ELISA testing is used).
No special diet is required.
FE-1 is specific to EPI.
Watery stools cause false positive result
due to dilutional effect.
Will not reveal other non-EPI related
causes of fat malabsorption.
• KEY POINT: Nutritionally significant malabsorption of fat can sometimes
occur without overt diarrhea—i.e., patients can be constipated.
• See Table 3 for a summary of clinical testing for fat malabsorption.
