Help with a Cholinergic Receptor question?

My professor asked us a question and I was out for a few days for training so I'm assuming I missed the lecture on it because I cannot for the life of me figure it out:

"Lomotil (Imodium) is an effective cholinergic receptor blocking agent that inactivates smooth muscle and hence functions quite efficiently as an antidiarrheal. Skeletal and cardiac muscles are also activated by cholinergic receptors yet Lomotil does not influence either muscle type. Explain why this is true based on what you know about neurotransmitters and receptor in the autonomic vs somatic motor divisions of the peripheral nervous system."

I would be truly thankful if anyone could explain this one to me. My exam is on Friday and I want to be sure I covered everything. Thank you so much!