A 41-year-old male presented to the ED for worsening abdominal pain over the prior three days. The patient described the pain as intermittent, sharp, and crampy in the upper quadrants. He reported constipation but denied fevers, nausea, vomiting, or diarrhea. He reported a past medical history of hypertension and neurofibromatosis. He denied prior surgeries, smoking, alcohol abuse, or illicit drug use. The vital signs were heart rate 94 beats per minute (bpm); respiratory rate 18 breaths per minute; blood pressure 159/90 millimeters of mercury (mmHg); temperature 36.5 degrees Celsius; and oxygen saturation 98% on room air. The patient appeared comfortable, but his physical exam was remarkable for tenderness in the upper abdomen without rebound or guarding. Murphy’s sign was negative, and no masses were palpated The remainder of his physical exam was unremarkable. The emergency physician ordered a complete blood count (CBC), comprehensive metabolic panel (CMP), lipase, urinalysis (UA), and computed tomography (CT) of the abdomen and pelvis with intravenous (IV) contrast. CBC, CMP, lipase and UA were within normal limits. The CT revealed no acute intra-abdominal process but revealed a stable, round focus of low attenuation adjacent to the celiac artery. This was thought to be a neurofibroma given the patient’s history and stable appearance from a CT performed nine years prior. The diameter of the opacified celiac artery was also similar to the prior study at 1.2 centimeters (cm). The patient was treated with one liter normal saline bolus and famotidine. On re-evaluation he was symptom free and informed of the results of the work-up that was performed. He was diagnosed with undifferentiated abdominal pain and counseled to return to the ED for worsening pain, the development of fever, uncontrollable vomiting, or any new concerns. The patient returned to the ED the next day for acute worsening of his pain that became diffuse and constant. He reported several episodes of non-bloody vomiting and several episodes of non-bloody diarrhea after taking milk of magnesia and a Fleet enema for his constipation. The vital signs were heart rate 75 bpm; respiratory rate 18 breaths per minute; blood pressure 170/95 mmHg; temperature 36.2 degrees Celsius; and oxygen saturation 100% on room air. The patient appeared very uncomfortable and was writhing in pain. He had diffuse tenderness on abdominal exam, but no palpable pulsatile masses or auscultated abdominal bruits. He had good distal perfusion to his extremities with distal pulses equal. Otherwise, his physical exam was unremarkable. CBC, CMP, lipase, lactic acid, and a CT angiogram of the abdomen and pelvis were ordered, along with IV opioid and fluids. The patient received multiple doses of opiate analgesia, including hydromorphone, without relief. CBC was remarkable for leukocytosis of 17.3 x 109 per liter (L) (normal range: 4.5 to 11.0 x 109/L), and lactic acid was 2.0 millimoles per liter (mmol/L) (normal range: 0.5 to 2.0 mmol/L). CMP and lipase were unremarkable. The CT angiogram of the abdomen and pelvis ( and ) revealed a 3.2 x 2.4 cm proximal CAA with surrounding inflammatory change and trace hemorrhage. The remaining vasculature was unremarkable. Upon return from CT, the patient’s status deteriorated. He became diaphoretic, tachycardic, and hypotensive. Point-of-care ultrasound revealed fluid in Morrison’s pouch. Central venous access was obtained and the patient was stabilized with four units of blood. He was transferred to a tertiary care facility for emergent surgical repair. The patient was brought to the operating room emergently at the tertiary care facility and underwent exploratory laparotomy. He was found to have a large retroperitoneal hematoma from a bleeding CAA. Both proximal and distal control was obtained, and the CAA was ligated. Intraoperatively he had an estimated blood loss of eight liters and received 20 units of blood by massive transfusion protocol. He developed a coagulopathy, and the bleeding could not be controlled. The area of bleeding was packed and the patient transferred to the post-anesthesia care unit with an open abdomen, vacuum-assisted wound closure for continued resuscitation. The patient had a do-not-resuscitate order placed by family and expired a few hours after surgery.