Faecal Fat Globules
Chemical Pathology
The Chemical Pathology Laboratory at GHNHSFT has discontinued its Faecal Fat Globule testing service
Notes
High levels of faecal fat can be seen in steatorrhoea caused by pancreatic, biliary and intestinal disorders, however faecal fat analysis has been withdrawn from most laboratories as the test has poor sensitivity and specificity and better tests have been developed. University Hospital Bristol NHS Foundation Trust have now also withdrawn this service stating that:-
- There are no recommendations on dietary fat intake, resulting in false negative results if fat intake is insufficient.
- The test only examines a small amount of faeces so cannot reliably be used to determine fat concentration throughout the sample.
- The test is highly subjective, relying on the opinion of a single operator of whether there are droplets of fat present.
- The test only stains ‘neutral fat’ – triglycerides. Free fatty acids produced by the metabolism of triglycerides by gut bacteria will not be detected.
- There is no external quality control (EQA) so we are not able to compare our performance with other laboratories. EQA is a requirement for all assays.
- Faecal pancreatic elastase analysis is recommended instead of fat globules as it is a more reliable marker of pancreatic insufficiency. Faecal fat globules analysis is now very rarely performed in any UK laboratory as the test has been superseded by elastase analysis.
Further information
To learn more about gastrointestinal malabsorption visit patient.co.uk
Faecal elastase in steatorrhoea article
Faecal Elastase - helpful in analysing steatorrhoea? NJMON 2004
For healthcare staff (Athens access required)
Evaluation of steatorrhoea BMJ Best Practice
How to use faecal elastase testing. N.Nandhakumar Arch Dis Child Educ Pract Ed2010;95:119-123 doi:10.1136/adc.2009.174359 (ADC Education and Practice article for healthcare staff)
Page last updated 26/02/2015