51. THE 24-HOUR INTRAESOPHAGEAL pH MONITORING: A CRITICAL REASSESSMENT

We evaluated the ability of 24-h intraesophageal pH monitoring in discriminating 78 patients(pts) with gastroesophageal reflux (GER) disease(GERD) from 22 controls (Cpts): 17 pts had GERD alone(Apts) and 61 GERD and esophagitis diagnosed by endoscopy and biopsy (B-pts). Mean(±SD) age (months) was 30.0±34.7 (A), 50.1±53.8 (B), 19. 0±29.1 (C). Total exposure acid time (% GER)(A: 5.4±2.9; B: 9.0±9.9, p 5′ to clear (A: 3.3±2.9; B: 5.7±5.5, p 5′ in the early post-cibal period (pcp)(respectively: 3.9±5.1% vs 2.1±1.9%, p 5′ in 47.1% of Apts and 41.0% of Bpts. We conclude that: 1)Acid reflux in the early pcp plays a role in the development of mucosal injury; 2) the 24-h intraesophageal pH test has a remarkable incidence of negative results that limit its sensitivity.