Faecal Fats is a laboratory test that measures the amount of fat in faecal samples (stools). It may be used to confirm a diagnosis of malabsorption, where fats and oils are not properly absorbed by the gastrointestinal system.
How the Test is Performed
The Faecal Fat test is a rather unpleasant procedure, which involves collecting 3 full days’ worth of faeces in a bucket with a lid, while consuming at least 100 grams of fat per day. The stool collection is then analysed in a laboratory. It is not really a necessary test when there is obvious fat malabsorption, but may be helpful in less obvious cases. This test rather unpopular and is rapidly being replaced by other tests of pancreatic function.
Medical Conditions and Symptoms
Faecal Fats is a test on the stools to measure the amount of fat in them. Usually, the body absorbs and digests fat very efficiently and there is no fat remaining in the stools. When normal absorption is affected, for example by diseases affecting the intestine or pancreas, so-called malabsorption results in stools which are oily or greasy, bulky and difficult to flush – steatorrhoea. The absorption of fat-soluble vitamins including vitamins A, D, E, and K can be affected because these vitamins are dissolved in dietary fat and are therefore absorbed along with fats.
Test Results Explained
Faecal Fats may be reported as:
- negative – normal – all fat absorbed by the body, none remaining in stools
- positive – indicating incomplete absorption of fat
The amount of lipid (fat) per 24 hours may be stated – this should normally be less than 20 mmol.
Also Known As
- Fat digestion test