Adam Sandler and his band of buddies engage in a second helping of infantile lowjinks in “Grown Ups 2,” a lazy, plotless excuse for a comedy that, minute for minute, probably contains a higher percentage of gags involving burps, barfing, urine, excrement, and farting than any other Hollywood product of recent vintage, which is saying quite a lot. But laugh-wise the results are meager: the ratio of hits to misses in the joke department certainly doesn’t exceed very low single digits, about the same as the I.Q. it would require to enjoy the movie.

In a way “Grown Ups 2” is remarkable, if only for a complete lack of narrative structure. It follows a single day in the lives of Lenny Feder (Sandler) and his childhood buddies Eric (Kevin James), Kurt (Chris Rock) and Marcus (David Spade). (Absent from the ensemble of the first movie is the fifth wheel, Rob Schneider. It’s frightening to think that Schneider would think any project beneath him, but he’s not the only smart person here. Taylor Lautner, who plays the leader of a bunch of egotistical, moronic frat boys, has chosen to go uncredited. And this from a fellow who was proud of the “Twilight” flicks.) Lenny has given up his gig as a Hollywood agent and moved back to his hometown, and seems to spend all his time hanging out with his buds, who may have jobs (Eric is a mechanic and Kurt a cable guy) but don’t give them much mind. So the movie becomes nothing more than a succession of sketches—most centered on the four friends, but some on their wives and kids, and with room for cameos by a lot of other old Sandler mates like Colin Quinn, Tim Meadows, Jon Lovitz and (most appallingly) Nick Swardson, as well as supporting turns from the likes of Steve Buscemi, Shaquille O’Neal, Georgia Engel and “Stone Cold” Steve Austin. The whole business ends at a big eighties party at Feder’s house, where everyone dresses up in period costumes that play the comic nostalgia card and those nasty frat boys show up. A big fight ensues to close things on a note of slapstick violence.

A genius like Jacques Tati could carry off this sort of rambling, episodic material with style and insight. But Sandler is, of course, no Tati. He slouches through the movie with an air of contempt for the audience, occasionally rousing himself to shout but otherwise just ambling along as if he couldn’t muster the energy to peddle the miserable material, which is as bad in the moments that aim at the heartstrings as those that go for the crotch. James and Rock are more animated, but only slightly, while Spade follows Sandler’s comatose lead. (One can understand his reluctance to invest too much in bits involving Marcus’ dalliances with a string of unsightly women and the sudden appearance of the sullen, Thor-like son he never knew he had, played by Alexander Ludwig.) Salma Hayek, Maria Bello and Maya Rudolph are pretty much wasted as the wives of Sandler, James and Rock, and the less said about the youngsters who play their children, the better.

In a movie that stoops as low as this one does for laughs, it’s difficult to point to what’s worst in it. But Swardson, whose solo atrocity “Bucky Larson: Born to Be a Star” was certainly one of the smelliest abominations to hit the screen in the last decade, seems a pretty safe bet. He plays a school bus driver who’s heavy into drugs, booze and every sort of “unconventional” behavior. You might want to avert your eyes whenever he makes an appearance—and when Sandler, James, Rock and Spade are forced by those frat guys to strip and jump off a cliff into a reservoir. Luckily the scene isn’t as revealing as it might be, but it’s quite bad enough. Not to mention unfunny.

As usual, what passes for direction from Dennis Dugan consists basically in his instructing Theo van de Sand where to point the camera before giving his cast free rein to do whatever they like for as long as they choose. The result plods, and doesn’t look especially good either. “Grown Ups 2,” like its predecessor, takes its place as yet another Hollywood example of arrested development, in terms of both its characters and its technical quality.