I must admit, I'm surprised no one has mentioned Ivor Biggun ("Doc" Cox) and "I've Parted (misprint)", so:

"I've farted, I've farted, I've made a trouser cough,
"I've whistled in me Y-Fronts, I've just peeled one off,
"I've blown my bowel bugle, I've ben eating peas.
"I've broken wind, I've dropped my guts. Open a window please."

Regards

Walrus