The role of duodenogastroesophageal reflux (DGER), once erroneously termed “bile reflux,” in causing esophageal mucosal damage has been an area of interest in both animal and human studies. However, because of the lack of appropriate techniques to accurately measure DGER, extrapolation of findings from animal studies to humans has been difficult to make. The recent advent of the Bilitec system (Metronics Instruments, Minneapolis, MN), an ambulatory bilirubin monitoring device, is increasing our knowledge of the specific role of DGER in esophageal diseases. Studies suggest that DGER without acid reflux may result in symptoms, but unless acid reflux is present simultaneously, it does not cause esophagitis. Therefore, therapies should aim at reducing both DGER and acid reflux. Studies show that this may be accomplished by antireflux surgery or the use of proton pump inhibitors, which by reducing gastric volume, decrease the damaging potential of both acid and DGER.