The owner of a drug store walks in to find a guy leaning heavily against a wall. The owner asks the clerk, Whats with that guy over there by the wall?
The clerk says, Well, he came in here this morning to get something for his cough. I couldnt find the cough syrup, so I gave him an entire bottle of laxative.

The owner says, You idiot You cant treat a cough with laxatives

The clerk says, Oh yeah? Look at him, hes afraid to cough