What family guy episode is it when stewie trains for the olympics?

What is the name of the episode and do they have it on itunes?

The episode is called "Peterotica". Sorry don't know if it's available on itunes.

"After reading an erotic novel, Peter gets the idea to write one himself. Carter gets sued for publishing Peter's book on tape and loses all his money, where he is forced to become a middle-class citizen. Meanwhile, Stewie tries to train for the Olympics."

Episode 101-Stewie kills Lois Continued Part One

Not sure on the itunes thing though

do u mean the one where he does his own commentary "Stewie Griffin on the beam, by the way this is totally not gay"

Thats the stewie movie later converted into three separater episodes, i believe that one is Stewie B. Goode