The unabsorbed sugars in stools are measured with this assay. It measures the body's capacity to digest carbs or to take in nutrients from meals and beverages. The diagnosis of sugar intolerances can be assisted by reducing drug analyses on stool samples. When diagnosing anomalies in the metabolism of carbohydrates, such as lactase and sucrose, the presence of reducing chemicals is helpful. If any of these symptoms are present, such as diarrhoea, bloody or mucusy faeces, stomach discomfort, fever, throwing up, etc., stool tests are conducted.