### Description

Fine and Ogunji developed a quantitative method for microscopically measuring fat in a feces. This generated a fecal fat droplet total size-number product, which shows a statistically linear correlation with chemically measured fecal fat output. The authors are from Baylor University in Dallas, Texas.

Method:

(1) Stool from a quantitative collection is homogenized.

(2) A 5 mm diameter sample is taken and mixed with 2 drops of 36% acetic acid and 2 drops of 1% Sudan III stain.

(3) The slide is placed over a hot plate until bubbles appear, and then it is removed. This is repeated for a total of 3 times.

(4) The slide is immediately examined at a magnification of 400x using an optical micrometer.

(5) Fields selected for counts show fat droplets but little if any opaque fecal debris.

(6) 5 fields are examined, counting the number of fat droplets fall into the following size ranges (see Table).

Size Range in microns

Average Size in Range

0 – 5

2.5

6 – 10

8

11 – 20

15.5

21 – 40

30.5

41 - 80

60.5

Fat particles > 80 microns are rare. For these:

(1) measure all of these globules in 5 microscopic fields

(2) calculate the average size

average number of fat particle in size range =

= (average count in 5 high dry microscopic fields)

weighted size-number product =

= (average size for range in microns) * (average number of fat particles in size range)

fecal fat droplet total size-number product =

= SUM(weighted size-number products for all size ranges)

Interpretation:

• minimum score: 0

• maximum score: > 4,000

Score

Significance

<= 200

normal range

201 - 475

mild steatorrhea

476 - 1,400

mild to moderate steatorrhea

1,401 - 2,400

moderate to severe steatorrhea

> 2,400

severe steatorrhea

from Figure 1 page 530

estimated fecal fat output in g per day (r = 0.89, P < 0.001) =

= (0.0303 * (product)) + 1.2

where:

• The slope of the line in Figure 1 is 0.303, but this gives too high a value when data is supplied.

Performance:

• The sensitivity is 94% and specificity of 95%.

Limitation:

• The measurement of the stool sample and the microscopic field selected for counting are sources of variability.