First there was “The Nanny Diaries.” Now we have what can best be titled “The Nanny Diarrheas,” or as image-conscious Universal Pictures prefers to call it, “Nanny McPhee Returns.”

First there was “The Nanny Diaries.” Now we have what can best be titled “The Nanny Diarrheas,” or as image-conscious Universal Pictures prefers to call it, “Nanny McPhee Returns.”

It’s a virtual poo-fest, a celebration of dung that does its duty to be literally the crappiest movie of what’s been a woeful summer.

The stuff is everywhere: on dresses, shoes and faces. But it’s most prevalent in a script by Emma Thompson that promotes bodily functions more than human intellect.

The movie, a sequel to the surprise 2005 hit “Nanny McPhee” – which Thompson also wrote and starred in as the snaggletoothed title character – makes no attempts to expand its one-(digestive)-track mind.

Her idea of humor is to call upon 75-year-old Dame Maggie Smith to lower her posterior onto a large mushy cow patty. So much for dignity among Oscar winners. What were they thinking? Or, more to the point, were they thinking at all?

Obviously not, considering how willingly Thompson and the fine supporting cast of Maggie Gyllenhaal, Ralph Fiennes, Ewan McGregor and Rhys Ifans get down in the muck to pander to the scatological minds of 6-year-olds.

It’s certainly a far cry from the original “Nanny McPhee,” which generated charm, intelligence and magic you could believe in. So why the change? I can only assume that either Thompson’s mind has regressed to the level of a dribbling idiot, or the suits forced her to dumb it down in order to gain financing. Given their respective track records, I’m going with the latter.

I can’t imagine a writer the caliber of Thompson (an Oscar winner for her clever, humor-filled adaptation of Jane Austen’s “Sense and Sensibility”) relying on this many rote storytelling devices.

Of course, the entire concept of Nanny McPhee is nothing but a rip-off of “Mary Poppins,” the magic-wielding babysitter with a carpetbag full of life lessons to impart.

The first time around, you forgave the lack of originality due to the immense appeal Thompson brought to McPhee, a hideous-looking woman who grew more attractive as her young charges grew less unruly and irresponsible. But this time such leniency is utterly unwarranted.

It starts off bad and gets worse, as Thompson and director Susanna White resort to a tired scenario about a wartime mother (Gyllenhaal) attempting to keep family and farm together despite repeated interference from her sleazy bother-in-law (Ifans) and the two spoiled brats her brother (Fiennes) sends to live with them.

A good movie – and by “good,” I mean one that respects a child’s intelligence – would have compassionately explored the trials of a mother stressed out by the absence of her away-at-war husband (McGregor) and her futile attempts to get five selfish, out-of-control children – including three of her own – to behave.

A good movie also would have made its points about children learning to sacrifice and think beyond themselves, without employing a menagerie of gaseous crows and excrement-gushing cows. But, of course, that would require a willingness to rise above the bowels of intestinal humor.

The only thing more incontinent are the story’s supernatural elements, which rely solely on cheap visual tricks: a sextet of synchronized-swimming sows doing their best Esther Williams impersonation; grains of airborne barley assuming the shapes of various animals. OK, they’re cute, but they do little, if nothing, to advance Thompson’s tenuous tale.

Ditto for the five young actors playing the little terrors Nanny McPhee must tame, under the auspices of her “five lessons” for turning rebellious kids into shiny, vacuous dunderheads.

These lessons, including learning to share and to work together, consume most of the film’s running time, but they are delivered as little more than empty platitudes, covered – like everything else – in a thick coat of bullpucky.

Al Alexander may be reached at