Two nuns walk into a liquor store and one asked the clerk for the biggest bottle of Irish whisky he had.
The clerk replied
"heck no sister, you nuns aren't supposed to drink that stuff!"

The nun said
"Well my son it is not for us you see, it is for Mother Teresa," then the nun whispers "She has the constipation's."

The clerk said
"Oh, in that case, it's on the house. Here's the biggest jug we have."
The nuns thank him, bless him, and leave.

A few hours later, as the clerk is leaving, he sees the same two sisters in the parking lot, rolling around and drinking the Irish whiskey. Appalled he goes over to them and says "You ladies lied to me! You told me it was for Mother Teresa for her constipation's!"

One of the nuns takes another swig, looks up at him and says
"You wanna know something buddy? She sure will shit when she sees us!"