Assessing Gastric Motility and Distention in Postoperative Gastrointestinal Surgery Using Bedside Gastric Ultrasound: Predicting Risk of Aspiration Pneumonia, Ileus, Return of Bowel Function

Patient population: Patients undergoing colorectal surgery will be enrolled prospectively (both cancer and non-cancer patients). Inclusion Criteria: * Patients aged \> 18 years of age * Patients undergoing colorectal surgery (both cancer and non-cancer) Exclusion Criteria: * Patients \< 18 years of age * Patients with previous gastric surgery * Patients with inadequate or difficult baseline gastric ultrasound images * Any other patient deemed a poor study candidate by the treating physicians Research Design/Protocol: We will perform postoperative point-of-care ultrasound examinations in colorectal surgery patients and will record gastric volumes at set time points, including preoperative and the morning of postoperative day 1. The surgical team, who will be blinded to the results of the ultrasound exam, will make decisions to advance diet, remove nasogastric tube, and begin oral medications based on standard clinical criteria. At the completion of the study we will determine if there is any association between gastric volume on ultrasound and patient complications, such as nausea/vomiting, replacement of nasogastric tube, aspiration of gastric contents, inability to tolerate solid diet, prolonged admission/length of stay, and other clinical outcomes. Outcomes: Our exploratory outcome measures will be tolerance of diet, replacement of NG tube, nausea/vomiting, time to flatus, aspiration pneumonia/pneumonitis, and length of stay.