So, the owner of this drug store walks in to find a guy leaning heavily against a wall.  The owner asks the clerk "What's with that guy over there by the wall?" and the clerk goes "Well, he came in here this morning to get something for his cough.  I couldn't find the cough syrup, so I gave him an entire bottle of laxative.  

The owner goes "You idiot!  You can't treat a cough with a bottle of laxatives.  

The clerk goes "***Of course you can!  Look at him; he's afraid to cough.***"