Time to wrap up 'Fockers' series

You know a comedy franchise has hit rock bottom when, within the first 15 minutes of a movie, you’ve been forced to watch an obese man receiving an enema and a 2-year-old boy projectile vomiting into the face of his dad.

So it goes with “Little Fockers,” the third and (let’s all cross our fingers here) presumably last installment in the series about the put-upon nurse Greg Focker (Ben Stiller) and his ex-CIA agent father-in-law Jack Byrnes (Robert De Niro).

Greg and his wife Pam (Teri Polo) are now happily, if busily married in Chicago, with their twins’ third birthday fast approaching. But our hero faces temptation in the form of Andi Garcia (Jessica Alba), a knockout pharmaceutical sales rep who wants Greg to become a spokesperson for a new male sexual enhancement drug called Sustengo.

Jack, meanwhile, is facing mortality: He’s recently suffered a heart attack, which — for reasons that make about as much as sense as everything else in this slapdash effort — only Greg knows.

The plot of “Little Fockers,” of course, is really just an excuse to assemble a bunch of familiar faces and allow them to schtick it up. At least on that score, “Little Fockers” obliges. Barbra Streisand, as Greg’s sex therapist mother, and Dustin Hoffman, as his “menopausal” father, endearingly hover around the edges, and Owen Wilson — who’s long been the best part of this series — once again returns as Pam’s ex-boyfriend Kevin, a Zenpreaching investment banker who’s forever in the throes of a spiritual crisis.