Johnny Knoxville reprises his role as octogenarian duffer Irving Zisman and teams up with his cherubic grandson Billy in this rude and riotous road trip movie

It’s been a while since we’ve heard from the Jackass frat house but they make a welcome return in this tournament of bad taste and low concept pranks with Johnny Knoxville playing an 86-year-old on a road trip across the US accompanied by his eight-year-old grandson.

Just-widowed octogenarian Irving Zisman seems like a kindly old duffer who has to take charge of cherubic Billy and deliver him across country to his waster dad because his drug-addicted mother is due in the clink.

Riding a noxious-looking mint green Lincoln Continental, the pair set off causing merry chaos wherever they stop. The hidden camera pranks come thick, fast and, usually, very odorously. There are unfortunate run-ins with a soda machine, an episode in a funeral home which is just plain wrong, a cringe-inducing ladies' night in a southern strip club, and a visit to a diner which ends with a coup de théâtre of, well, gross incontinence.

For me the popcorn-in-nose snort eruption comes when Granpa Iriving gets on board a coin-operated fun ride outside a shopping mall. So far, so funny but when the duo invade and enter one of those truly disturbing child beauty pageants popular in the bible belt, Bad Granpa actually ascends to the realm of brilliantly executed satire. Albeit brilliantly executed satire with fart jokes.

Knoxville, in the best make-up job since Dustin Hoffman in Tootsie, is great and he reprises his role as Granpa with a prat-fall physicality, while Jackson Nicoll as Billy is both cute and mischievous as he gamefully takes advantage of the kindness of strangers.

In between the usual low-concept pranks, the story is filled out with a more conventional narrative as the two bond after initial distrust and dislike. Bad Granpa even becomes quite touching in places, whereas most Jackass projects are quite molesting and abusive everywhere.

This is just great good fun for the naughty child and the peeved-off senior citizen in everyone. Leave your manners at the box office and your brain in the U-bend.

Alan Corr