One of the reasons Joyce uses extensive scatological language in his Ulysses is that he invented a narrative strategy for satire by converting the purgative function of excrement to an artistic end. This is evidenced in his claim for his satirical broadside "The Holy Office" (1904) that his duty as artist is "Katharsis-Purgative." This paper investigates what, in Ulysses, Joyce satirizes by the excremental references, how he employs various excretory images, and finally, the politics of his scatological satire. This investigation focuses on the fact that Ulysses is set in 1904 when Ireland was a colony of the British Empire. Joyce, a postcolonial writer, first contemptuously derides English colonial culture for the reason that "the brutish empire" is nothing but the produce of "cloacal obsession." And he also ridicules, with excremental language and actions, domestic problems such as the hypocrisy of the press and deplorable emotionalism of his fellow countrymen, neither of which is, in his estimation, free from the imperialists` remote manipulations. As satire is, as characterized by Jonathan Swift, not malice but medicine, so does Joyce`s satire appear to be reflective of his repressed desire that all the repressive factors caused from both without and within Ireland have to be purified as early as possible. In this regard, Joyce`s excremental satire is an efficacious narrative strategy to promote, as he put it, "the spiritual liberation of my country."