The Fructose and Lactose Intolerance Breath Test is a non-invasive diagnostic tool used to identify intolerances to fructose and lactose, sugars found in many foods and beverages. The test works by having the patient consume a solution containing either fructose or lactose. Following consumption, the patient breathes into a device at predetermined intervals, usually every 15 to 30 minutes, over a period of two to three hours. The device measures the levels of hydrogen and methane in the patient’s breath, gases that are produced when these sugars are improperly digested and fermented by bacteria in the gut. Elevated levels of these gases can indicate fructose or lactose intolerance, providing important information for dietary adjustments and symptom management.