the common standards for abnormality (less than or equal to 2.8 mm2/mmHg and less than or equal to 2.0 mm2/mmHg). Fisher's exact analysis was completed to determine whether abnormal IRP and abnormal DI are related. Results: In patients with a normal IRP (, 15) as measured by HRIM, the mean DI was 4.02 with a standard deviation of 2.89. In patients with abnormal IRP ( $ 15), the mean DI was 3.03 with a standard deviation of 2.58. The difference in the mean DIs was statistically significant (p-value 5 0.0234, t-test) . Table illustrates the number of patients in each IRP and DI subgroup using both cutoff standards. There was no statistically significant difference in the observed patient frequencies of any classification than would be expected by chance. Conclusion: We found that a normal IRP (, 15mmHg) is associated with higher DIs and that an abnormal IRP ($15 mmHg) was associated with a DI # 3.1. However, abnormal DI by the standards of either cutoff was not related to having abnormal IRP. Our data supports that both a high IRP and reduced DI suggest impaired LES relaxation, but a DI of less than 2.0 and 2.8 does not predict an IRP of less than 15 mmHg, suggesting some variability between the two metrics. While the chi-squared analysis approached but did not achieve statistical significance in this study, repetition with larger sample sizes in the future may yield a clearer relationship between abnormal IRP and abnormal DI.