When Roddy Doyle's debut novel The Commitments was first published in 1987, it was a new voice in the Irish writing of the time. Unlike his mostly disconsolate peers, Doyle took pleasure in observing life as it's actually lived, combining an utter lack of interest in worn-out tropes of Catholic guilt or spiritual stagnation with the sharpest and most generous ear for Dublin speech since Flann O'Brien. The good news is that, in The Guts, these gifts are still intact.

The book picks up the story of Jimmy Rabbitte Jr, the closest thing The Commitments had to a protagonist. Now 47 instead of 22, Jimmy has spent the intervening quarter-century hustling music and starting a family, but he's just been diagnosed with bowel cancer. And here's the problem.

Previous Barrytown novels patiently rotate around a simple central situation: Jimmy gets a band together, Sharon has a kid, Jimmy Sr goes to work for his best mate. 'Jimmy Jr gets cancer' would have been a perfectly good situation in itself, but for no very clear reason, Doyle chooses to throw in a sub-story about an adulterous affair. On top of that, Ireland's economic crisis has been felt so acutely that no writer as honest as Doyle could avoid confronting it one way or the other. The result is a full-blown plot, in which Jimmy devises a rather improbable scheme to rescue his business from collapse.

The result is a structural mish-mash. There are passages of scalding writing, such as Jimmy's mortified reaction on encountering his much-more-seriously-ill mate Outspan in the cancer ward, but the extra-marital shenanigans, poignant as they are, come from nowhere and go nowhere, while Jimmy's business wheeze has a caper element which seems to belong to a less ambitious book.

It's still highly enjoyable. Jimmy's wife Aoife is the latest in Doyle's line of sharp women characters, while the subtle distinctions between Jimmy's, Aoife's and their children's various modes of speech are the kind of thing that he does better than any other Irish writer. It's good to have Jimmy back, still mischievous even when fearing death, neither burned out nor faded away. But The Guts feels like part of a bigger story as yet untold, and since it apparently isn't one, that's frustrating.