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
Which of the following drugs inhibits the release of acetylcholine from cholinergic nerves in the submucosa and myenteric complex 
Select and explain. 
A. Pectin, B. Docusate, C. Loperamide, D. Cholestyramine
C: Loperamide
Answer: C: Loperamide 
Explanation: Loperamide:- It is an opiate analogue with major peripheral u opioid and additional weak anti-cholinergic propey. As a constipating agent it is much more potent than codeine. Because of poor water solubility--little is absorbed from the intestines. Entry into brain is negligible--CNS effects are rare and occur only with high doses; no abuse liability. The duration of action is longer (12 hr). Ref:- kd tripathi; pg num:-686