This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gastrointestinal tract, Subject name: Pharmacology
[{'content': 'Drug used in hepatic encephalopathy is: \nSelect and explain. \nA. Magnesium sulphate, B. Lactulose, C. Bisacodyl, D. Bisphosphonates', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Lactulose is a laxative that acts by conversion to sho chain fatty acids in the colon. These fatty acids resulrs in decrese in PH of intestinal juice. At low PH ammonia becomes ionized and thus cannot be absorbed.', 'role': 'assistant'}]