Fart training is a thing that happens.
Farting is a huge component of your arsenal in The Stick of Truth.
Cartman teaches you your first few, but as the game progresses you'll need to develop a stronger retinue of flatulence based weaponry.
Enter Terrance and Philip. You must travel to the backwards realm of 'Canada' and prove your worthiness to Terrance and Phillip so that they may teach you the mightiest of all farts, The Nagasaki.
They even go as far as offering the following caveat for ass-based combat,
”Don’t ever, ever fart on a man’s balls.”