Yesterday I was in the doctor's waiting room and I heard a ninety-six-year-old man pleading with the doctor for a lower sex drive.
'Surely you're imagining things,' said the doctor. 'You're ninety-six years old. Isn't all the feeling for sex just in your head?'
'Yes,' replied the elderly man, 'that's why I want you to lower my sex drive to the place where it might do more good.' Full text

Patient: 'Doctor, doctor! I've just swallowed a whole sheep.'
Doctor: 'How do you feel?'
Patient: 'Quite baa-d.' Full text