A 50-year-old male presents to the emergency department with a 3-hour history of bloody emesis. He has no such prior history. The vomiting was not preceded by retching. He states that the blood was bright red. He currently feels slightly dizzy. He has no history of alcohol use. He has noted intermittent epigastric pain for the past 2 weeks that is relieved by taking oral antacid pills. On review of systems, the patient notes that he injured his knee a month ago and has been taking ibuprofen daily for pain relief. Physical exam reveals a blood pressure of 100/60 mmHg and a heart rate of 110/minute. There are no signs of jaundice, and the abdomen is flat. No hepatosplenomegaly, caput medusa, or spider veins are appreciated. Laboratory values reveal a hematocrit of 40%. Liver function tests are normal, as are international normalized ratio (INR) and partial thromboplastin time (PTT). Blood urea nitrogen (BUN) is 36 mg/dL, and creatinine is 1.0 mg/dL.