Innovative Cough Treatment

A Chemist walks back into his shop after a short break and sees a man leaning against the wall.
"What's wrong with him?" he asks his assistant
"He wanted for syrup but I couldn't find any so I gave him a bottle of laxatives" says the assistant.
"You idiot" you can't treat a cough with laxatives"
"Of course you can" replies the assistant, "look at him, he's too bloody scared to cough"