“Popeyes customer pulls out a gun after being told there were no more chicken sandwiches.” – CNN.com headline

The chicken sandwich is the hamburger of the 2010s and can inspire grown human beings to lose their minds, as evidence by the recent madness over the newly introduced Popeyes chicken sandwich.

As Morgan Spurlock points out in his new documentary “Super Size Me 2,” there are around “20 billion chickens clucking around the globe” right now.

Super Size Me 2: 3 out of 4 CST_ CST_ CST_ CST_ CST_ CST_ CST_ CST_ Samuel Goldwyn Films presents a documentary directed by Morgan Spurlock and written by Spurlock and Jeremy Chilnick. Rated PG-13 (for brief strong language). Running time: 93 minutes. Opens Friday at the Gene Siskel Film Center and Sept. 13 on demand.

What the cluck.

Some 15 years ago, Spurlock burst onto the scene with his clever and entertaining and sobering documentary “Super Size Me,” which chronicled a 30-day period in which Spurlock ate only McDonald’s food and experienced not only the expected weight gain, but mood swings, skyrocketing cholesterol and (TMI) sexual dysfunction.

This launched Spurlock’s career as a celebrity documentary filmmaker in the vein of Michael Moore, a TV personality and producer, and a guy who, while clearly talented and with much to say, has a hard time surrendering the spotlight to anyone but Morgan Spurlock.

In “Super Size Me 2: Holy Chicken!,” Spurlock revisits the fast food industry, in particular “Big Chicken,” aka the top broiler producers, led by Tyson Foods Inc., from the inside out via the launch of his own quick-serve chicken joint in a former Wendy’s in Columbus, Ohio.

“How did a guy like me get into a business like this?” Spurlock asks in voiceover — and away we go on another Morgan Spurlock comedic adventure, which turns out be an informative and eye-opening reality check delivered in a largely whimsical wrapper.

We follow Spurlock as he visits big-name franchises such as Wendy’s and Popeyes and Burger King and even 7-Eleven (which offers what looks to be a horror show of a chicken sandwich) as well as neighborhood favorites such as “Bakesale Betty’s.”

Spurlock, after taking a bite of a Burger King chicken sandwich: “All I can say is, there’s a reason this place is called BURGER King.”

When Spurlock asks which menu item is healthiest, the answer is always: the grilled chicken sandwich. When he inquires as to the most popular item, the answer is always: the crispy sandwich.

(We learn “crispy” has replaced “fried” as the go-to term for restaurants, because “fried” has such a negative connotation.)

During the slick and funny and light opening segments, we’re almost holding our breath waiting for the inevitable sequences where we see adorable, fluffy, little newborn baby chicks living in “grow houses” for a short while (just six weeks!) before …

You know. They’re slaughtered and they (or should we say, parts of them) quickly reach their final destination as Menu Item #6 or Today’s Special at your favorite fast-food joint.

As Spurlock learns the ins and outs of starting a chicken restaurant, we learn along with him as he experiences what it’s like to be a chicken farmer, and how the advertising industry has bombarded us with nebulous terms such as “free-range” (there’s no legal definition of “free range”) and “all-natural” and “artisan grilled” and “made without additives” and “fresh-cracked eggs” to make us feel better about the “eating healthy,” or at least relatively healthy.

And yes, we see a series of nauseating visuals of artificially grown chickens suffering from all manner of ailments, including heart attacks, because they get so big so fast.

Spurlock’s comedic antics give way to a more serious, traditional docu-journalist approach as he looks into the immensely unbalanced dynamic between the Big Chicken corporations and the local American farmer, which often results in the farmer carrying generational debt. It’s nothing we haven’t heard before, but it’s still heartbreaking to see small farmers telling their individual stories about the financial and emotional stress they’ve experienced.

By the time Spurlock opens his “Holy Chicken” restaurant featuring “hormone-free, antibiotic-free, cage-free, free-range, farm-raised, humanely raised, 100 percent natural” items and a policy of utter transparency, with signage such as, “By painting these walls this lively shade of green, we’re helping you believe our food is fresh and natural,” we’ve lost our appetite for any type of chicken product.

But that doesn’t mean we won’t succumb to temptation the next time we walk past a fast-food restaurant and catch a whiff of their famous spicy chicken sandwich.