A little old lady goes to the doctor and...
A little old lady goes to the doctor and says, "Doctor I have this problem with gas, but it really doesnt bother me too much. They never smell and are always silent. As a matter of fact, Ive farted at least 20 times since Ive been here in your office. You didnt know I was farting because they didn't smell and are silent."

The doctor says, "I see. Take these pills and come back to see me next week."

The next week the lady goes back, "Doctor," she says, "I dont know what the heck you gave me, but now my farts...although still silent they stink terribly."

"Good", the doctor said, "Now that weve cleared up your sinuses, let's work on your hearing."

An invisible man is here to see you
Nurse: Doctor, there is an invisible man in your waiting room.

Doctor: Tell him I can't see him now. Next.