This test detects reducing sugars (e.g., lactose, glucose, galactose, fructose) that remain unabsorbed in the intestine.

When carbohydrates are not properly digested or absorbed, they pass into stool and can be detected chemically.

Clinical uses include:

Diagnosing lactose intolerance and other disaccharidase deficiencies.

Evaluating chronic diarrhea in infants and children.

Supporting diagnosis of malabsorption syndromes (e.g., celiac disease, short bowel syndrome).

Monitoring patients with suspected carbohydrate malabsorption.

Often performed alongside stool pH, stool osmolarity, and stool microscopy for comprehensive GI evaluation.

Analyte: Reducing sugars in stool (qualitative or semi‑quantitative).

Normal Result: Negative (no reducing substances detected).

Abnormal Findings:

Positive test: Indicates carbohydrate malabsorption (e.g., lactose intolerance, sucrose intolerance, glucose‑galactose malabsorption).

High levels: Seen in infants with diarrhea due to enzyme deficiencies or GI infections.

Clinical Use:

Provides a simple marker of carbohydrate malabsorption.

Helps guide diagnosis and management of pediatric GI disorders.

Supports gastroenterology and nutrition evaluations.