Sentence:  The move to out-and-out <WSD>scatology</WSD> in humorous texts for junior readers takes off in the later 1990s, following the overt scatological humor of ground-breaking ‘bum and poo' picture books for younger readers, such as Holzwarth's "The Little Mole Who Knew It Was None of His Business" (1998). 
Meaning of the word marked with <WSD> tags:  Literature, humor, or pornography featuring excrement or excreting.