The Gleesons are a lively double-act, and the scatological jokes arrive at an impressive clip

In Frank of Ireland (Channel 4, Thursday), Domhnall Gleeson and Brian Gleeson are two stars looking at the gutter. Channel 4s new sitcom, which the brothers co-scripted, is an over-caffeinated chortle-fest characterised by often shockingly low-brow humour. The jokes arrive at an impressive clip  and with an almost obsessively scatological quality.
The last time the siblings acted together was with father Brendan in Enda Walshs The Walworth Farce. Here, by contrast, theyre having a go at a post-Celtic Tiger Dumb and Dumber with striking if generally icky results. The upshot is that if you like lowest-denominator slapstick, youll love it to bits. If not, you may wish the giggling Gleesons had challenged themselves to write gags that didnt involve cadavers and male appendages.
Brian plays Frank, a struggling, self- hating troubadour living at home in Malahide. His ultimate ambition is a concept album eulogising all 32 counties of Ireland (potential song titles: Blood Is Thicker Than Waterford and the Witches of East Wicklow  to which I would humbly suggest they add Roscommon People). Doofus (Domhnall) is his best friend who has a thankless retail job and helps Brian flog CDs on the side.
Written down, many of the jokes feel misanthropic rather than witty. A disastrous attempt by Frank to relaunch his music career by singing Michael Finnegan at a funeral culminates, for instance, in a fight with the mourners. Meanwhile, the brothers have so much fun quoting Harvey Keitels sweary dialogue from Taxi Driver they reference it twice.
Domhnall is, of course, a Hollywood star. And its fair to say that here he is stretching acting muscles he was not required to employ in Star Wars or Richard Curtiss About Time.
Filling out the cast is Sarah Greene as Áine, the ex Frank cant stop sleeping with, and Tom Vaughan-Lawlor as her Ross OCarroll-Kelly-esque boyfriend Peter-Brian. Pat Shortt, meanwhile, is required to bare all as Áines father when Brian finds him seeking comfort after his mothers death in the arms of Brians mam (Pom Boyd).
The Gleesons make for a lively double- act, and the series functions best when they are riffing off each other. The high quips-per-minute ratio ensures episode one of six zips by. But its the timbre of those gags that could potentially prove a stumbling block to some. Frank of Ireland has more potty humour than you can shake a toilet brush at, and so viewer mileage may vary.