Brad Leithauser at The New Criterion:
The body of his verse gives us a remarkably full autobiographical portrait. In this, he’s somewhat unusual. American poetry in the twentieth century abounded in wonderful poets from whose collected poetry it would be hard to concoct even a sketchy biography: John Crowe Ransom, T. S. Eliot, Marianne Moore, Weldon Kees, Louise Bogan, Elizabeth Bishop, Randall Jarrell, Donald Justice. For such writers, we must turn to their letters or to outside biographers to satisfy our hunger about the workings of their daily and their inner lives. But in Updike’s case, he is often most openly and freely himself in poetry. He comes to it with an assured ease, instinctively constellating his thinking in that reverse Heaven whose stars are black balls of type and whose sky is the unbroken field of whiteness between stanzas.
I’m tempted to call what he does naked poetry, not least because he so often focused on erotic and bodily functions. He wrote poems called “Fellatio” and “Squirrels Mating” and “Mouse Sex” and “Elderly Sex” and “Cunts” and “Two Cunts in Paris” and “Klimt and Schiele Confront the Cunt”; he wrote a poem about a memorable defecation (“The Beautiful Bowel Movement”) and gave us a detailed account of a colonoscopy. You could say that he offered us his body. It’s in his poetry that we learn which hand he relied upon to perform which intimate ministrations.
more here.