Fecal Fat

Test for steatorrhea or excess fat in bowel movements due to fat. Helps to estimate the percentage of dietary fat that the body does not absorb

Normal range: <7 g of fat per 24 hours

Use

Aids in the diagnosis of malabsorption

As a follow-up to other stool tests and blood tests to investigate the cause of chronic diarrhea and loose, fatty, foul-smelling stools (steatorrhea)

Interpretation

A person who consumes 100 g of fat per day would have an average stool fat of <7 g/24 hours. Fecal excretion of more than 7 g of fat in a 24-hour period or more than 7% of the measured fat intake over a 3-day period is indicative of fat malabsorption or steatorrhea malabsorption.

Increased In

The absence or significant decrease of the pancreatic enzymes, amylase, lipase, trypsin, and chymotrypsin limits fat, protein, and carbohydrate digestion, resulting in steatorrhea due to fat malabsorption.

The underlying condition of steatorrhea includes

Celiac disease

Chronic pancreatitis

Crohn disease

Cystic fibrosis

Gallstones (cholelithiasis)

Pancreatic cancer

Pancreatitis

Decreased In

NA

Limitations

For a 72-hour stool collection, 50 " “150 g of fat a day for 2 " “3 days prior to and during the stool collection period needs to be consumed. The fat should be long-chain triglycerides (such as corn or olive oil, not butter).

False-positive results can occur due to mineral oil or castor oil present in the specimen.