This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': 'When a patient is admitted with severe upper abdominal pain, the diagnosis of acute pancreatitis should not be accepted until each of the following conditions has been ruled out except: \nSelect and explain. \nA. Acute cholecystitis, B. Acute renal colic, C. Adhesive small bowel obstruction, D. Mesenteric embolization', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Acute pancreatitis is a diagnosis of exclusion. Its symptoms and signs are not readily distinguishable from other severe upper abdominal problems. Adhesive small bowel obstruction does not present marked peritoneal signs unless bowel gangrene is also present.', 'role': 'assistant'}]