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': 'In which of the following condition is spastic ileus seen? \nSelect and explain. \nA. Porphyria, B. Retroperitoneal abscess, C. Hypokalemia, D. MI', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Spastic, or dynamic ileus is rare and results from extreme and prolonged contraction of intestine. It is seen in: Heavy metal poisoning Uremia Porphyria Extensive intestinal ulceration Ref: Harrison 17/e, Page 1912.', 'role': 'assistant'}]