I learnt this song as:

Gonorrhea
I went and stuck it in her rear (Audience: "Wrong hole!")
And now my urine isn't quite so clear
Oh, I believe in Gonorrhea

Public Lice
Damn things near as big as mice
And I tell you they're not very nice
Oh, I believe in Public Lice

Syphalis
It all started with a little kiss
Now it hurst when I try to piss
Oh, I believe in Syphalis

Leprosy
Bit are falling off of me (Audience: "Just the tip!")
I'm not half the man I used to be
Oh, I believe in Leprosy

Amputees
They're already on the knees
Just the height to slide it in with ease
Oh, I believe in Amputees

Birth Control
When having children quite you goal
But you want to cum in every hole
Oh, I believe in Birth Control