Current practice for measuring esophageal and gastric pH: The current catheter based 24-hr pH system involves placement of a catheter into the esophagus and stomach via the nostril. The tip of the catheter has sensors to measure esophageal and gastric pH. The patient is then sent home (after the catheter is placed, tip coming out of one nostril) and is given a box that measures pH exposure. This is uncomfortable to the patient, leading to change in their daily activities, diet, etc. with resulting data probably not reflective of their "daily habits". Moreover, since the catheter is passed blindly into the esophagus and stomach, the exact location of pH measurement is probably not accurate.