This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: AIIMS 2018, Subject name: Pharmacology
Morphine should not be used in the treatment of: 
Select and explain. 
A. Ischemic pain, B. Biliary colic, C. Cancer pain, D. Post operative pain
B: Biliary colic
Answer: B: Biliary colic 
Explanation: Morphine (an opioid) is a strong analgesic. It is used in treatment of all types of pain like Crush injury, Fracture, MI, cancer pain, post-operative pain etc. However in Biliary colic (e.g. due to any stone blocking bile duct), morphine constricts sphincter of Oddi and increase the intrabiliary pressure. This increases the chances of rupture of bile duct. Therefore opioids like morphine are contra-indicated in biliary colic.