YIH-FU SHIAU, M.D., Ph.D.; GEORGE M. FELDMAN, M.D.; MICHAEL A. RESNICK, D.O.; PHILIP M. COFF, M.D.
Stool osmolality and electrolyte measurements were obtained from 12 patients with diarrheal disorders. Osmolality of diarrheal stool (285 to 330 mosmol) regardless of the cause is less than the reported osmolality of normal stool. Storage of stool at room temperature can artifactually increase stool osmolality as the result of bacterial metabolism. When stool samples are fresh, a negative osmotic gap (measured osmolality - 2 X [Na + K]) is commonly associated with secretory diarrhea, whereas a high osmotic gap (greater than 160 mosmol) is seen in patients with osmotic diarrhea. In many conditions fasting does not resolve diarrhea completely, and when the stool osmotic gap is greater than 50 mosmol, the pathogenesis of diarrhea is difficult to define.
Learn more about subscription options.
Register Now for a free account.
SHIAU Y, FELDMAN GM, RESNICK MA, COFF PM. Stool Electrolyte and Osmolality Measurements in the Evaluation of Diarrheal Disorders. Ann Intern Med. 1985;102:773–775. doi: 10.7326/0003-4819-102-6-773
Download citation file:
Published: Ann Intern Med. 1985;102(6):773-775.
Results provided by:
Copyright © 2017 American College of Physicians. All Rights Reserved.
Print ISSN: 0003-4819 | Online ISSN: 1539-3704
Conditions of Use
This PDF is available to Subscribers Only