The ability to assess the complex motor functions of the gastrointestinal tract accurately has been of tremendous value to understanding and treating digestive diseases. Unlike other smooth or cardiac muscle organ systems with relatively more rhythmic and patterned motor behavior, the complexity of the diverse motor behaviors of the alimentary canal have made the development and use of clinical and preclinical tests of gastrointestinal motor function a great challenge. It is perhaps this complexity, as well as the importance of gastrointestinal function to overall health and well-being, that have fascinated early physiologists and continue to push modern physiologists and clinical diagnosticians to develop new and more accurate measurements of motility.