A very bawdy passage from Piers the Ploughman (c1380) that made me laugh in a childish way:
"By that time, Glutton had put down more than a gallon of ale, and his guts were beginning to rumble like a couple of greedy sows. Then, before you had time to say the Our Father, he had pissed a couple of quarts, and blown such a blast on the round horn of his rump, that all who heard it had to hold their noses, and wished to God he would plug it with a bunch of gorse!"
William Langland trans. J. F. Goodridge