A small prick does the job

Don't laugh!" said the patient, Jim.  "Of course I won't laugh," the  doctor said, "I'm a professional.  In over 20 years, I've never laughed at a  patient."  "Okay, then," Jim said, and proceeded to drop his  trousers, revealing the tiniest 'whoo-ha' the doctor had ever seen. It  couldn't have been bigger than the size of an AAA battery.  Unable  to control himself, the doctor started giggling, then fell laughing to the  floor. Ten minutes later he was able to struggle to his feet and regain his composure.  "I'm so sorry," said the doctor. "I really am. I don't know  what came over me. On my honor as a doctor and a gentleman, I promise it  won't happen again. Now then, what seems to be the problem?" "It's  swollen," Jim replied. Merrily