A collection of devices intended to be used for carbon-13 breath analysis to investigate suspected gastrointestinal disorders [e.g., gastric emptying disorder (gastroparesis), H. pylori infection]. It consists of an ingestible carbon-13 labelled substrate and breath specimen containers. The test relies on the metabolism of the substrate and expiration of carbon-13 isotopes in CO2. It can be administered by a healthcare professional in a clinical setting and alternatively by the patient at home; the collected expired breath sample is analysed by an infrared or mass spectrometry analyser (not included) in a clinical laboratory or at the point-of-care. This is a single-use device.