Girls Trip: largely terrible, crazily overlong party comedy

Something very strange happens about midway through this largely terrible, crazily overlong party-down comedy. The wildest of the caning-it women kneels beside the bed and begins thanking God for giving her such great chums. The rest of the party then joins her in a group prayer. There's no joke here. The incident leads to no further plot developments. You wouldn't get that in Absolutely Fabulous.

Girls Trip is full of peculiar shifts in attitude and philosophy. This is a film that – in one of its best moments – features torrential urination from a very great height. Yet it ends with a speech so pious and on-the-nose that one half expects it be followed by a few verses of What a Friend We have in Jesus. It is proud of its shout for personal independence. But it is desperately in thrall to the corporate and the conventional.

Four old friends, each with a single defining characteristic, travel to New Orleans for the annual Essence Festival (the urge to insert a trademark symbol here is close to irresistible). The always-welcome Queen Latifah is a compromised gossip columnist. The gifted Tiffany Haddish is sexually uninhibited. The flinty Jada Pinkett Smith needs to loosen up. Regina Hall, playing the closest to a developed character, is trapped in a bad marriage with an adulterous athlete. You will get some notion of the subtle writing when you hear that Hall's inspirational book is actually called You Can Have it All. They may as well have titled it Self Help Tome #543.

Fillet out the uncritical genuflections to the Essence Festival and the barely mediated celebrity cameos and you may be left with a tolerable 90-minute romp. The camera rejects no opportunity to include the logo of the soft-drink company that sponsors the event. Such personalities as Sean "Diddy" Combs, Mariah Carey, Doug E Fresh and – most bizarrely – director Ava DuVernay turn up just so as they can turn up.

Meanwhile, the broad characters wee, roger and grind their way towards absurdly satisfactory solutions to their neatly defined personal issues. Annoying cop-show funk plays beneath every supposed joke.

No film with a cast this strong could fail to raise laughs. But the actors are wasted in a huge bloated mess that is far too convinced of its own moral rectitude. Forgive them, father.