A thin, ﬂexible tube (about the diameter of a spaghetti noodle) is directed through the nose and down the esophagus, where it’s positioned in the esophagus. The outside of the tube is taped to the nose and worn for the next 24 hours. During this time, it records the pH (level of acidity) and impedance (whether there is liquid present) in the lower esophagus. The patient can eat and drink normally with it in place. After 24 hours, the tube is removed, and the data is analyzed. We use this to quantitate the severity of GERD. Unlike the Bravo capsule, this method can record both acidic and nonacidic reﬂux, though some prefer that less-invasive method instead of having a small tube down their nose for a day.