THE CHANGE-UP Review

If you fling poo in the first scene of your movie, you've established both your tone and your target audience. The Change-Up, which does just that, thereafter seldom wavers from its bold mission statement, to the delight and merriment of all those who enjoy humor that prizes profanities and bodily fluids above all.

That is, until the movie begrudgingly displays a weird kind of conscience, hinting that the flimsy main characters who have been running around making silly faces have souls and, you know, genuine feelings. The hilarity grinds to a halt while the actors look sensitive and justify to themselves why they took the roles in the first place: Because they wanted to prove they're not just funny people, damn it.

What makes The Change-Up occasionally bearable are moments of inspired lunacy, in which real life is tossed on the trash heap and the action leaps into absurdism, as in a late night kitchen sequence featuring twin babies doing unspeakable things to household appliances. Early on, Jason Bateman and Ryan Reynolds catch fire; they appear to be riffing like jazz musicians on the lines that have been written for them; either that, or their delivery is so gracefully off-the-cuff that it resembles the spontaneity of improvised comedy.

Those moments are few and far between, however, stranded like intelligent thoughts in a vast idiotic wasteland.

At heart, The Change-Up is nothing more than an R-rated "body switch" movie, but the problem is that writers Jon Lucas and Scott Moore, responsible for The Hangover as well as Four Christmases and Ghosts of Girlfriends Past, were more ambitious than that. (To be fair, someone else might have insisted on fleshing out the more serious aspects of the story.) Whoever is responsible for that decision, it stops the movie in its tracks.

The two main characters, Dave Lockwood (Jason Bateman) and Mitch Planko (Ryan Reynolds) are portrayed as men in crisis. Dave is a family man, married to the long-suffering Jamie (Leslie Mann), and father of three, including baby twins. He has a great job, makes a big salary, and is up for partner in his firm.

But he doesn't seem to be enjoying life. He's worn out from having poo flung in his face, and he wishes he could act on his lustful impulses toward sexy co-worker Sabrina (Olivia Wilde).

Really, Dave wishes he could have the relaxed single lifestyle enjoyed by Mitch. Mitch is an actor (of sorts), bangs all the chicks he wants, and does whatever he wants every day. But he, too, longs for a different life. His father (Alan Arkin) occasionally stops by to express his disapproval and disappointment; Mitch wishes he had a family that cared only about him, maybe a wife and children who were waiting for him to come home at night.

One drunken bout later, Dave and Mitch yell out that they wish they had the other guy's life while they are simultaneously urinating into a fountain in a park late at night. Lightning strikes, the power goes out, and presto change, they wake up in the body of the other.

It proceeds from there pretty much the way you'd expect. The fountain is moved to an unknown location, so Dave and Mitch must try to make the best of the situation. Initially, this leads to some of the aforementioned riffing, which is amazingly silly yet so rapidly paced by director David Dobkin (The Wedding Crashers, Fred Claus) that it feels like harmless fun.

But the laughs become much more scarce as the inventive, silly spirit runs dry, washed aground by the genuinely sad demeanor of Jamie, who feels that the happiness of her marriage to Dave has been slowly deflating for years. Of course, once the movie stops for Jamie to express her sorrowful concerns at length, we know it's only a matter of time before Mitch's father must stop the movie again to express his sorrowful concerns about his son's wasted potential.

It's heavy-duty soap opera poured onto a very thin premise that wasn't that funny or fresh to begin with.

The Change-Up opens wide across the U.S. today. Check local listings for theaters and showtimes.