You run into the stall and close the door.
"Uhhh..." the man outside says. Your face rapidly changes into a canine form, you can't respond in English.
"Bluuhhhgghhhh!!!" you say, tilting yourself over the toilet bowl.
"Oh....Uhhh...I'll...I'll just-" the man says. At that moment, your spine starts readjusting itself again, bringing your face closer to the toilet bowl.
"Bluuggghhh!" you say again. You hear the front door to the men's room close. You're alone once again, but now you have another problem. You want to drink the toilet water.
But that would be gross...wouldn't it?