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
Spastic ileus is seen in 
Select and explain. 
A. Porphyria, B. Retroperitoneal abscess, C. Hypokalemia, D. MI
A: Porphyria
Answer: A: Porphyria 
Explanation: 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.