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': 'Sulfa drug used in inflammatory bowel disease includes: \nSelect and explain. \nA. Sulfasalazine, B. Sulfamethoxazole, C. Sulfinpyrazone, D. Sulphadoxine', 'role': 'user'}, {'content': 'Answer: A \nExplanation: the azo bond is split by colonic bacteria to release 5ASA and sulfa pyridine .the former exes a local antiinflammatory effect ESSENTIALS OF MEDICAL PHARMACOLOGY SEVENTH EDITIION KD TRIPATHI PG NO 683', 'role': 'assistant'}]