Reading from behind: a cultural analysis of the anus

In a playful, yet scholarly romp through "low" and "high" culture, Jonathan Allan asks why--since we all have one and use it every day--do we squirm at the mere mention of the anus?

How is it that Kim Kardashian's derriere can break the internet, Pippa Middleton's behind can create a "butt lift" craze, and yet we cannot handle a discussion of anality? And why, given that we all have one, has the anus been caught up in the very "ground zero of gayness"?