A man goes to the doctor and says: "Doctor, there's a piece of lettuce sticking out of my bottom." The doctor asks him to drop his trousers and examines him. The man asks, "Is it serious, doctor?" The doctor replies, "I'm sorry to tell you but this is just the tip of the iceberg."
In Richard Wiseman's online collection and rating of jokes study (2001) for the
University of Hertfordshire (
Laughlab), this was the joke that the
British participants found funniest.