This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pharmacology
The following adverse drug reaction seen in colonoscopy view is due to 
Select and explain. 
A. Cascara, B. Bisacodyl, C. Castor oil, D. Loperamide
A: Cascara
Answer: A: Cascara 
Explanation: The picture shows Melanosis coli caused by Senna and cascara which are stimulant purgatives.bisacodyl usually cause hypokalemiaRef: KD Tripathi 7th ed pg 673