Chloride, Feces

Test Code

8831

CPT Codes
82438

Preferred Specimen

10 mL random watery liquid fecal collected in a plastic screw-cap container, or 24-hour, 48-hour or 72-hour watery liquid fecal collected in a plastic screw-cap container

Minimum Volume

2 mL

Instructions

Submit a frozen specimen of watery liquid feces in a plastic screw-cap container. Keep feces refrigerated during collection and transport frozen. Only watery liquid feces are an acceptable specimen. In the event a formed fecal specimen is submitted, the test will not be performed and will be cancelled.

Note: Specimen must be shipped frozen to reduce the odor during shipping and to minimize the risk of the container rupturing due to gas accumulation.

This test only has clinical utility if performed on a watery fecal specimen.
Stable up to 3 freeze-thaw cycles

Transport Temperature

Frozen

Specimen Stability

Room temperature: Unacceptable
Refrigerated: 7 days
Frozen: 60 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Specimens in paint cans • Formed stool • Specimen received refrigerated

Methodology
Coulometric Titration

Setup Schedule

Monday-Friday Morning Report available: Next Day

Reference Range

See Laboratory Report

Clinical Significance

Measurements of chloride in conjunction with other electrolytes in liquid stool may help differentiate between secretory and osmotic diarrhea. This test may also aid in the diagnosis of primary or secondary chloridorrhea.

Diarrhea can be categorized as secretory or osmotic depending on how the water content of stool is drawn in the intestine lumen. Secretory diarrhea is caused by defective electrolyte absorption that increases the stool's electrolyte levels. Conditions associated with secretory diarrhea include infection, neuroendocrine tumors, intestinal resection, diffuse mucosal disease, and congenital chloridorrhea [1]. Congenital chloridorrhea is a rare autosomal-recessive disorder characterized by watery stool containing excessive chloride. Stool chloride levels during perinatal period and infancy are often greater than 120 mmol/L [2]. Similar to congenital chloridorrhea, acquired chloridorrhea may manifest as hypochloremia, metabolic alkalosis, and no chloride in the urine, but the magnitude of excess chloride excretion in the stool is usually less [3].

Low levels of stool chloride may be seen in sodium sulfate-induced diarrhea [4].

The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.

References
1. Schiller LR. Pract Res Clin Gastroenterol. 2012;26(5):551-562.
2. Konishi KI, et al. J Pediatr. 2019;214:151-157.e6.
3. Kaplan BS, et al. J Pediatr. 1981;99(2):211-214.
4. Eherer AJ, et al. Gastroenterology. 1992;103(2):545-551.

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.