Test Overview
Test Methodology


Test Usage

Testing for reducing substances in stool is used in diagnosing the cause of diarrhea in children. Increased reducing substances in stool are consistent with primary or secondary disaccharidase deficiency and intestinal monosaccharide malabsorption. Similar intestinal absorption deficiencies are associated with short bowel syndrome and necrotizing enterocolitis. Stool reducing substances is also helpful in diagnosing between osmotic diarrhea caused by abnormal excretion of various sugars as opposed to diarrhea caused by viruses and parasites.

Reference Range *

Negative. A result of 0.25% to 0.5% is suspicious for a carbohydrate absorption abnormality, >= 0.75% is abnormal.

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

Test Limitations

Assay results have relevance for liquid stool samples; assay results have little relevance for formed stool samples. Salicylates, penicillin, streptomycin, cephalosporins, ascorbic acid may interfere with assay and/or cause false positive results.

Test Details
Days Set Up
Soft Order Code
MiChart Code
Reducing Substances, Stool
Chemical Pathology
Special Chemistry
Specimen Requirements
Collection Instructions

Collect liquid stool in a plastic urine container or screw top stool container. Refrigerate. Do not collect and dispense from disposable diaper; stool liquid (which would be absorbed in diaper) is most important part of sample. Formed stool not acceptable.

Normal Volume
10 mL liquid stool.
Minimum Volume
3 mL liquid stool.
Additional Information

The Clinitest® reaction detects all reducing substances in stool; of primary interest are glucose, lactose, fructose, galactose, maltose, and pentose.

CPT Code
Fee Code