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: Medicine
[{'content': 'All are features of irritable bowel syndrome except - \nSelect and explain. \nA. Vomiting, B. Pain abdomen, C. Diarrhoea, D. Constipation', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]