Urinalysis and Body Fluids 6th Edition by Majorie DiLorenzo, Susan Strasinger

Exercise 32

The fecal osmotic gap is elevated in which disorder?

A. Dumping syndrome

B. Osmotic diarrhea

C. Secretory diarrhea

D. Steatorrhea

Step 1 of 2

Fecal osmotic gap:

To determine the reason of diarrhea, the osmotic gap is calculated.

• The fecal sodium, and potassium is determined to find the osmotic gap

• Low osmotic gap is associated with secretory diarrhea

• High osmotic gap implies osmotic diarrhea

• If the osmolality is above 50 Osm/kg (osmoles per kilogram) then it is due to osmotic diarrhea

• If the osmolality is less than 50 Osm/kg then it is due to secretory diarrhea

Therefore, the disorder, which elevates the osmotic gap is “osmotic diarrhea”. Hence, the correct answer is option.