Test Overview
Test Methodology

Inductively Coupled Plasma Optical Emission Spectrometry (ICP/OES)

Test Usage

Compliance or Abuse Monitoring of Laxatives

Reference Range *

MAGNESIUM: Magnesium concentrations in stool water above the normal levels of 0.7 - 1.2 mg/mL have been indicative of surreptitious abuse of magnesium containing laxatives. NMS Labs Calculated Normal: approximately 0.5 - 10 mg/g. PHOSPHORUS: Phosphorus concentration in stool water averaged 1.8 +/- 0.3 mg/mL (ranged from 0.3 - 4.2 mg/mL) following administration of 105 mmol of sodium phosphate. NMS Labs calculated normal: approximately 1.4 - 22 mg/g.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Details
Days Set Up
Varies, Monday, Tuesday, Wednesday, Friday
Analytic Time

7 - 12 days

Soft Order Code
  • Phosphorus, Stool
  • Magnesium, Stool
Reference Laboratory
Mayo FCLPF (NMS 1033ST)
Special Testing
Specimen Requirements
Collection Instructions

Collect random stool specimen and refrigerate.

Normal Volume
10 grams (solid) or 10 mL (fluid) stool
Additional Information

Test includes Magnesium [FAAS] and Phosphorus [ICP/MS]. Test sent to Mayo Medical Laboratories; performed by NMS Labs.

CPT Code
80103 x2, 83735, 84100