In theaters

ALONG CAME POLLY, written and directed by John Hamburg, 90 minutes, rated PG-13.

Early in “Along Came Polly,” the new gastrointestinal comedy with Ben Stiller and Jennifer Aniston, it’s revealed that Stiller’s character, Reuben, suffers from an acute stomach disorder, the likes of which tend to keep him rooted to the toilet should he eat the wrong sort of food.

Naturally, since this is one of those movies, Reuben, an uptight risk management expert, is exposed to everything he can’t and shouldn’t eat, with the end results being predictably noisy, disastrous and oh, so calamitous.

But not funny.

At my screening, each of Reuben’s bathroom blowouts was met with the sort of impatient silence normally reserved for those in the company of a stranger’s misbehaving child. Indeed, if audiences came to “Along Came Polly” to see sparks fly between Stiller and Aniston, what they got instead was the less-favorable “Along Came Diarrhea,” with poor Polly lost somewhere in between.

As written and directed by John Hamburg, the film follows Stiller’s Reuben, a recently married schmuck whose wife, Lisa (Debra Messing), cheats on him on their honeymoon with Claude (Hank Azaria), a French nudist cum scuba diver who’s known, shall we say, for his rather impressive snorkel.

Crushed, Reuben returns alone to New York, where he eventually reconnects with his old schoolmate and polar opposite, Polly, who loves to salsa, has a blind ferret for a pet, and who enjoys her share of spicy foods, which she eats with her unwashed fingers while encouraging Reuben to do the same.

Between them, young love and bacteria bloom. Reuben’s great challenge is to let go of his phobias and give in to Polly’s more bohemian ways; Polly’s great challenge is to allow love into her life; and the audience’s great challenge is to get through the movie, which is only slightly buoyed by supporting performances by Philip Seymour Hoffman as a former child star and Alec Baldwin as Reuben’s boss.

Like the dullest, most banal comedies, “Along Came Polly” will likely come and go without leaving its mark. Few will remember it and those who see it might wish they hadn’t.

On to the next movie.

Grade: D

On video and DVD

OPEN RANGE, directed by Kevin Costner, written by Craig Storper, based on the novel “The Open Range Men” by Lauran Paine, 135 minutes, rated R.

In the Western “Open Range,” director, producer and star Kevin Costner casts himself in a variation of the role that has defined so much of his career: that of a troubled loner whose reluctance to become romantically involved is exactly the quality that makes him so irresistible to strong-willed women.

He’s Charley Waite, a quiet, brooding man guiding cattle across the wild West with three other free-rangers: the patriarch of the group, Boss Spearman (Robert Duvall), gentle giant Mose (Abraham Benrubi) and the immature Button (Diego Luna).

After a leisurely opening that drags in spite of the welcome diversion of cinematographer James Muro’s stunning, wide-open landscapes (the film was shot in Alberta and its look is pure John Ford), the movie gets under your skin.

Working against the men as they move along the outskirts of Harmonville is a powerful, insidious rancher named Baxter (Michael Gambon), who detests free-rangers so much, he employs several men to find Charley, Boss and the others with the intent to kill them.

What ensues is a gathering storm, one that culminates in a vicious, beautifully conceived gunfight that matches anything in “High Noon” or “Unforgiven,” along with a stiff romantic undercurrent that pulls the film together as Charley falls for Sue Barlow (Annette Bening), the local doctor’s handsome, headstrong sister.

Time and failure have turned Costner into a generous actor and director. Throughout “Open Range,” he literally hands his movie to Duvall, who runs with the film, doing some of his best work in years, walking a fine line between grounding the movie as Charley’s moral compass while offering several much-needed moments of comic relief. He’s terrific here and one of the best reasons to see the movie.

Some of the film’s dialogue is unfortunate (“I’ve been holdin’ my love a long time, Charley”; “Let’s go rustle up some grub”), and Costner remains the sort of cornball softy who can’t resist forcibly tugging at our hearts. Still, for the most part, he’s more sure-footed than ever, mining a memorable posthumous performance from Michael Jeter, delivering a solid turn himself and finding in the Western something grand, familiar and new within a genre that clearly has some life in it yet.

Grade: B+

Christopher Smith is the Bangor Daily News film critic. His reviews appear Mondays and Fridays in Style, 5:30 p.m. Thursdays on WLBZ 2 and WCSH 6, and are archived at RottenTomatoes.com. He can be reached at BDNFilm1@aol.com.