BACKGROUND: Lung transplant patients are at risk of developing chronic lung allograft dysfunction (CLAD) of which bronchitis obliterans syndrome (BOS) is the most common. These patients also are noted to develop gastrointestinal (GI) disease. Gastroesophageal reflux disease (GERD) is implicated in BOS, and diagnosis and treatment of GERD may help to decrease incidence of BOS. METHODS: A total of 131 lung transplant recipients with post-transplant evaluation between 2012 and 2019 were studied. Of 60 post-transplant evaluations with at least 6 months of post-transplant follow-up that included impedance testing, high-resolution manometry (HRM), and pH testing, procedures were performed according to recognized standards. RESULTS: Of 60 patients, 56 (93%) were alive at 1-year post-transplant. The patients were found to have high rates of GI motility diseases: 37 patients (62%) had abnormal impedance testing, 50 patients (83%) had abnormal HRM results, 22 patients (37%) had abnormal pH test results. There was associated high rejection rates in patients with abnormal esophageal motility. There were 37 patients that had abnormal impedance test results and of those 25 patients (67%) developed rejection. Fifty patients had abnormal post-transplant HRM studies, 33 (66%) had an acute cellular rejection episode. Twenty-two patients had abnormal pH results, with 14 (63%) having an acute cellular rejection. CONCLUSIONS: Patients undergoing lung transplantation were found to have increased incidence of abnormal GI motility studies of the esophagus. These patients were further found to have increased rejection rates and BOS which has been associated with worsened mortality. Developing a formalized pre- and post-transplant motility study process, using evolving technologies for these patients, may provide guidance of at-risk patients for CLAD and early treatment to prevent CLAD.