Ah, Bobby and Peter Farrelly. Those giants of gross out. Those titans of the toilet bowl. Those pharaohs of the fart joke.

The world may have changed a fair whack since the brothers Farrelly began amusing and disgusting audiences in 1994’s Dumb & Dumber, but their trademark irreverence shows no sign of ageing. Their talent, no sign of maturing.

Hall Pass reminds audiences that while each of the Farrellys have now celebrated their womb extraction anniversary more than 50 times they are certainly not above a well-timed shart joke. Remember Dumber & Dumber’s outrageous Lloyd-Bridges-on-laxatives bathroom gag? You could plop that directly into Hall Pass and it wouldn’t look out of place.

The premise is a no-brainer: two best friends get granted one week’s “hall pass” by their wives. One week’s guilt-free vacation from marriage to do as they please. S-x, alcohol, golf, buffalo wings, hash cookies. Whatever.

Rick (Owen Wilson) and Fred (Justin Sudeikis) are chuffed to receive such a gift from their special someones (The Office’s Jenna Fischer and Christina Applegate) who dosh them hall passes after Rick is busted checking out other women’s butts and Fred is caught masturbating in his car by the fuzz (the latter moment is reminiscent of a scene in There’s Something About Mary in which a fireman is rather amused to discover Ben Stiller’s testicle caught in his zipper. Back we go to timeless toilet bowl comedy territory: it was funny then and it’s funny now, though in both instances timing played a major part).

Rick and Fred decide to get laid pronto and hit the town to carve up the dance floor and woo some ladies, but they soon take heed of geriatric Indiana Jones’s shibboleth — “not as easy as it used to be” — and awkward interactions with the opposite s-x ensue. When all appears to be lost, a veteran ladies’ man and parody of Sherlock Holmes (Richard Jenkins) arrives on the scene. Amusingly, he can deduce the likelihood of a woman going to bed with them by observing the marks on her fingertips, the bulges in her bag, her poise, the way she moves her mouth, etcetera.

Hall Pass’s wild sense of humour keeps the proceedings unpredictable, even as the story ebbs towards familiar emotional territory. The overlapping but only lightly flogged “love your partners for who they are” message feels more authentic than expected, especially given the Farrellys have always struggled to pull off any substance or serious side (no matter how diluted). Credit goes largely to Wilson, whose affable nice guy presence has a mellowing effect and provides some balance to the Farrellys’ trademark trashiness.

There’s more than a touch of 2009’s The Hangover to Hall Pass; it’s in the same breed of dopey male-driven comedy. The characters are of Flight of the Conchords anti-cool ilk (though a decade or so older) and keep the movie’s irreverent sense of humour kicking along. The gags in Hall Pass are an unpredictable mixture of dialogue, gross outs and absurdity, and a lot of the time, they work. The hilarious final scene (hint: don’t leave when the end credits appear) is a fitting reminder that when the Farrellys are on, they’re on.

The details: Hall Pass opened in cinemas nationally on Thursday.