The present invention is directed to a device that measures volatile organic compounds (VOCs) emitted by an individual's urine, feces or present in flatulence for use in assessing the individual's health. The device may be part of a toilet. The device includes a gas sensor that measures VOCs in the air within the toilet bowl after waste is deposited therein. The device includes a manifold that keeps air from the toilet bowl separate from water and waste in the toilet bowl until the gas sensor has collected readings. Then the manifold combines the air, water, and waste before depositing the material into the sewer system. The gas sensor may be connected to a processor that analyses the gas sensor readings, provides a report of the analyzed data, and transmits the data to a network. A healthcare provider may download the data from the network to assess the individual's health.