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': 'Spastic ileus is seen in \nSelect and explain. \nA. Porphyria, B. Retroperitoneal abscess, C. Hypokalemia, D. MI', 'role': 'user'}, {'content': "Answer: A \nExplanation: Answer is 'a' i.e. Porphyria Spastic, or dynamic ileus is rare and results from extreme and prolonged contraction of the intestine. It is seen in - heavy metal poisoning - porphyria - uremia - extensive intestinal ulceration.", 'role': 'assistant'}]