From the Research
For a 70-year-old patient presenting with sudden abdominal tenderness, normal abdominal ultrasound and examination, but low hemoglobin, the initial approach should be option C: Abdominal CT. This imaging modality is most appropriate as the first step because it can rapidly identify potentially life-threatening causes of acute abdominal pain with associated blood loss, such as abdominal aortic aneurysm, mesenteric ischemia, or intra-abdominal hemorrhage. The combination of sudden abdominal tenderness with low hemoglobin suggests active bleeding that requires immediate evaluation. While endoscopy/colonoscopy and stool testing are valuable diagnostic tools, they are not the optimal initial tests in this acute presentation where rapid diagnosis is essential. CT can visualize the entire abdomen and retroperitoneum, detect active bleeding sources, and guide further management decisions. After the CT scan, depending on findings, endoscopy or colonoscopy might be appropriate follow-up investigations if a specific gastrointestinal source is suspected but not definitively identified on CT, as suggested by studies on the diagnostic accuracy of fecal immunochemical tests for colorectal cancer 1, 2, 3, 4, 5. Key considerations include the sensitivity and specificity of these tests, as well as their role in risk-stratified symptomatic patients, highlighting the importance of a tailored approach based on clinical presentation and risk factors 5. However, in the context of acute abdominal pain with low hemoglobin, the immediate concern is to identify and manage life-threatening conditions, making abdominal CT the most appropriate initial step.