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': 'Not true regarding Irritable bowel syndrome \nSelect and explain. \nA. Improvement with defecation, B. Most common is diarrhea followed by constipation, C. Onset associated with a change in frequency of stool, D. Onset associated with a change in form of stool', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Most common is constipation followed by diarrhea.', 'role': 'assistant'}]