Currently, there are five emergency physicians (EP) on staff in the York Hospital ED who are fellowship trained in POC US. These physicians are fully credentialed and are already performing ED based evaluations for small bowel obstruction. We intend to evaluate the performance of EP-performed POC US in the diagnosis of SBO in ED patients. This study would primarily investigate the accuracy of ultrasound as compared to the criterion standard of abdominal CT results, intraoperative diagnosis, or discharge diagnosis.