Our hypothesis is that small amounts of GER can move back up into the esophagus and get inhaled into the lungs, and may be one of the triggers for lung scarring. We propose to look for certain substances normally only found in the stomach in the "exhaled breath condensate" which is collected by breathing comfortably into a cooled cylinder, allowing the breath to condensate. In a smaller group of patients, we also plan to perform a bronchoalveolar lavage, a more widely studied test in which a small amount of fluid is introduced into a small part of the lungs through a fine tube, and then removed for examination, to evaluate whether the two tests provide similar measurements. We will also evaluate the correlation between these molecules and other tests, including lung function, and markers of lung scarring activity, and tests to look at how the esophagus is working so that we can get a clearer picture of how this affects patients' daily lives. Finally, we will be following up patients over time with lung function to see whether evidence of GER into the lungs is linked with a greater likelihood of worsening of lung scarring in the future.