Newborn lamb as a new model for studying gastroesophageal reflux.

We aimed to determine whether the newborn lamb at term is a valid model for studying gastroesophageal reflux. Seven bottle-fed lambs, ages 2 to 3 days, underwent esophageal multichannel intraluminal impedance-pH monitoring (MII-pH). A total of 196 reflux episodes were recorded, including 73% alkaline and 27% weakly acidic. No acid refluxes were observed. Median bolus clearance time was 4  seconds (3; 5.5), and proximal reflux extent was 35% (26). This first report of MII-pH in the newborn mammal sets the foundations for future studies with physiological and clinical relevance to human neonates.