Fecal Fat

This is a test performed on the stool to find out how much fat is in the stool. Usually when the stool contains a lot of fat, it will indicate that fat is going through the body at an increased rate. This is often seen during problems of malabsorption. This is a condition in which the body is not able to absorb foods well enough.


Usually 100 grams of fat per day is suggested for 3 days prior to and throughout the period of stool collection. The grams of fat suggested are lower for children and infants. You will need to defecate (have a bowel movement) in a dry, clean container. Do not urinate or put toilet paper in the stool container. No laxatives or enemas should be used during the period of the stool collection.


  • Fat: 2-6 g/24 hr or 7-21 mmol/day (SI units)

  • Retention coefficient: greater than or equal to 95%

Ranges for normal findings may vary among different laboratories and hospitals. You should always check with your doctor after having lab work or other tests done to discuss the meaning of your test results and whether your values are considered within normal limits.


Your caregiver will go over the test results with you and discuss the importance and meaning of your results, as well as treatment options and the need for additional tests if necessary.


It is your responsibility to obtain your test results. Ask the lab or department performing the test when and how you will get your results.