While preventing the development of a POI is most important, POIs still occur; therefore, it is important to definitively diagnose a POI as early as possible during the post-operative course for treatment to prevent patient discomfort, complications, and extended hospital stay. The purpose of the G-Tech study is to determine if the G-Tech Device can detect a difference in the myoelectric signals from patients who develop a POI compared to those patients who do not develop a POI. It is anticipated that up to 20% of patients enrolled in this study and consented preoperatively, excluding screen failures, will show evidence of a post-operative ileus as detected by the G-Tech GutCheck Device and differentiate the myoelectric signals from the patients who do not develop a POI. Patients who are known to have developed a POI may also be selected for the study.