Introduction: Acute ischemia of the bowel is associated with mortality rates of up to 80%. While early detection is key to appropriate management, the utility of investigative modalities is limited by poor sensitivity and specificity. Objectives: This report outlines the case of a patient with investigation results unremarkable for underlying ischemia, where clinical suspicion alone led to its diagnosis. Case Report: A 37-year-old female presented to a tertiary hospital ED with severe, generalized, abdominal pain for several hours after eating at a restaurant. She had a known history of treatment for breast cancer, as well as dihydropyrimidine dehydrogenase (DPD) deficiency. On examination, the patient was tachycardic and she had vague tenderness was in the right upper and left lower quadrants. A venous blood gas demonstrated normal lactate. Initial CT abdomen and pelvis with intravenous (IV) contrast showed minimal bowel edema only. Pain persisted despite high-dose opioids, and was out of proportion to physical examination. Despite a second CT angiogram revealing no vascular occlusion or ischemia, persistent pain prompted a diagnostic laparotomy, uncovering an infarcted duodenal segment, necessitating resection and anastomosis. Post-op, the patient recovered well and was discharged without complications. Discussion: This case highlights the importance of clinical suspicion in diagnosing bowel ischemia. Typical risk factors such as advanced age, atrial fibrillation, coagulopathy, cardiac disease, or a low-flow state were not present in this patient. Abdominal pain is present in around 95% of patients with mesenteric ischemia. Despite a myriad of proposed lab markers and diagnostic modalities, very few have shown to be reliable at identifying mesenteric ischemia. Diagnosis of mesenteric ischemia relies on a high index of suspicion in a patient with abdominal pain, especially one that is out of proportion and possibly associated with postprandial worsening. Conclusion: In the acute care of patients with potentially life-threatening conditions, especially bowel ischemia, care must be taken into account for the most important cause for severe pain. If conventional markers for disease do not show typical abnormalities, it does not always exclude the diagnosis. Clinical gestalt for an unwell patient takes precedent and should always guide disposition decisions.

Keywords: Mesenteric Ischemia; Emergency Department; Abdominal Pain