Prolonged wireless pH monitoring increases diagnostic yield in patients with reflux symptoms and borderline 24-hour impedance pH.

The Lyon Consensus defines pathological gastroesophageal reflux disease (GERD) as an acid exposure time (AET) greater than 6%, while AET less than 4% rules it out. AET between 4% and 6% is borderline. Prolonged wireless capsule pH monitoring may enhance GERD diagnosis, though it is not widely used in Latin America. This study aimed to categorize patients with borderline AET as GERD or non-GERD using prolonged wireless capsule pH monitoring, assess treatment response, and compare tolerance and interference with 24-hour impedance testing. Thirty-three patients with persistent reflux symptoms and borderline AET (4%-6%) from a 24-hour impedance study were included. Exclusions were prior esophageal surgery, major motility disorders, or unreliable impedance tests. A 96-hour off-proton pump inhibitor (PPI) wireless capsule pH monitoring was performed. Patients were categorized as GERD (AET >6% for 2+ days) or non-GERD (AET <4% for 4 days). Treatment was based on these categories, and GerdQ scores were assessed at baseline and 8 weeks. Three patients were excluded due to incomplete data. Of the 30 patients, 16 (53%) were classified as GERD, 6 (20%) as non-GERD, and 8 (27%) remained borderline. Wireless capsule monitoring provided a diagnosis in 73% of borderline cases. GERD patients responded well to PPI optimization, while non-GERD patients benefited from neuromodulation. Tolerance and daily activity interference were better with wireless capsule monitoring. Prolonged wireless capsule pH monitoring effectively categorized over 70% of borderline AET patients, leading to improved treatment outcomes with good patient tolerance.