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': "A 36-year female complaints of abdominal pain & constipation since 5 years. She has on & off rectal bleed when she tries to defecate forcefully. The most probable diagnosis is: \nSelect and explain. \nA. Ulcerative colitis, B. Crohn's disease, C. Tuberculous intestine, D. Irritable bowel syndrome", 'role': 'user'}, {'content': "Answer: D \nExplanation: The findings are consistent with irritable bowel syndrome. Crohn's disease would typically have perianal fistulae while ulcerative colitis has periods of acute disease and quiescent periods: the acute periods are severe and may lead to significant impairement.", 'role': 'assistant'}]