EndoFLIPTM is used as a diagnostic test that provides a three-dimensional image to measure the diameter of the esophagus, as well as the pressure inside it. For example, it will measure the width of your esophagus as well as the internal pressure. The ratio of these two numbers is referred to as the distensibility, or the capacity to swell as a result of pressure from inside the organ.
The test is similar to an endoscopy where a camera and device are fed through your mouth and fluid is released through a catheter with specialized sensors. This diagnostic test is useful to help determine the cause of difficulty swallowing.