Gastroesophageal reflux disease (GERD) has been postulated to result in chronic aspiration contributing to the development of chronic lung disease, otherwise known as bronchopulmonary dysplasia (BPD) in premature infants. This association has been indirectly based on anecdotal improvement in the respiratory status of infants with BPD after anti-reflux therapy, but the direct causal relationship has been difficult to prove. In addition, the historical evidence for infants with GERD has been based on acid reflux only which is diagnosed by 24 hour intra-esophageal pH monitoring, the gold standard. However, with the introduction of multi-channel intraluminal impedance (MII), GERD can now include non-acid reflux. The contribution of non-acid reflux to the development of BPD in premature infants is unknown. As our understanding of GERD has improved, previous assumptions regarding the efficacy of therapy may no longer be valid. The utilization of anti-reflux surgery (fundoplication) for the treatment of BPD in premature infants with GERD has not been rigorously studied. The efficacy of fundoplication in this patient population has yet to be determined.