This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Large intestine, Subject name: Surgery
[{'content': "Duhamel's operation is done for: \nSelect and explain. \nA. Hirschsprung's disease, B. Meconium ileus, C. Annular pancreas, D. Imperforate anus", 'role': 'user'}, {'content': "Answer: A \nExplanation: Duhamel's operation - done for Hirschsprung's disease The Duhamel procedure was first described in 1956 as a modification to the Swenson procedure. A Retrorectal approach is used, and a significant segment of aganglionic rectum is retained. The aganglionic bowel is resected down to the rectum, and the rectum is oversewn. The proximal bowel is then brought through the retrorectal space (between rectum and sacrum), and an end-to-side anastomosis is performed with the remaining rectum", 'role': 'assistant'}]