Mondo Cane (literally "A Dog's World") spawned numerous imitators and created a subgenre of its own: mondo. These movies featured wide-ranging subject matter: aberrant sexual behavior; voodoo and witchcraft; scenes of violence and death; and—most objectionably—the actual slaughter of animals.
Since many of these films included scenes that were recreated, or dramatized, for greater shock effect, opportunistic filmmakers decided that the next logical step would be to make movies that provided the gross-outs their audiences hungered for tethered to an actual storyline that would be more dramatically compelling than the freewheeling documentary style. The resulting genre became known as the cannibal vomitorium, and—whew—they can be extremely tough to watch.
There are three main storylines for vomitoriums. In one, a "civilized" person (or persons) crash-lands in a remote jungle and is set upon by primitive, flesh-eating natives. In the second, students travel to said location to do research on the natives and end up as the main course. In the third, and truest to the mondo model, filmmakers hit the jungle to film a documentary about the natives and...well, you get the idea. They're never heard from again, and their footage is later salvaged and screened by their horrified peers, thus forming the structure of the narrative. Keep in mind this was decades before The Blair Witch Project freaked out moviegoers in 1999.
A constant in all these films is that the protagonists must endure every sort of atrocity, including imprisonment, sexual assault, the amputation of a body part and full-on consumption. What makes these pictures particularly reprehensible is their blend of staged mayhem and authentic animal mutilation, causing a great deal of controversy and allowing their distributors to proudly crow, "Banned in 50 countries!"
I've seen a few of these movies on video, and I'm sure it's a completely different experience than watching them with a live, stoned, screaming audience on 42nd Street (where a lot of them played for years). One of the most notorious, Umberto Lenzi's Cannibal Ferox, aka Make Them Die Slowly (1980), was re-released in 1997 by Grindhouse, a distribution company owned by Sylvester Stallone's son Sage. It played some theatrical dates, but I bought it on laserdisc, unable to resist the temptation of seeing "the most violent film ever made," according to the publicity. It also came with a 45 RPM single of the theme song and a vomit bag. Hey, I can't resist effective marketing!
A Man Called Horse-style hanging. If you've seen that film, you know what I'm talking about.
This is not a film I revisit fondly (although I do wish I'd attended one of those midnight screenings to see the hysteria), but I put it on when I'm with like-minded friends, just to see how much they can take. Lenzi claims that he initiated the vomitorium cycle when he made Man from Deep River in 1972. His parents would be proud.
Cannibal Holocaust (1981) follows much the same formula, except it uses Plot "C" (filmmakers shooting a documentary), and includes special effects so shocking—including a native girl impaled from stem to stern on a pike—that the director was dragged into court to prove that it wasn't real. Interestingly, some critical response at the time was positive and it still gets a 67% (fresh) on RottenTomatoes!
Although it's acclaimed as an attack on society's ills (by those who acclaimed it), I think it's nastier than Ferox. Along with the aforementioned piking scene, it really ladles on the animal attacks.
A lesser pic in the genre, Il Rei di Morti-Viventi (1979), which was released to U.S. drive-ins as Dr. Butcher, M.D., brings cannibals and zombies together. It's a hodgepodge starring Ian McCullough from Fulci's Zombi 2. It seems that patients are turning up with limbs missing in New York hospitals and—huh?—the culprits are traced back to a remote Caribbean island where a mad doctor is making zombies out of cannibals. Now that's what I call recycling! Fortunately, the vomitorium cycle only lasted a few years, although recently Deodato attempted to raise financing for an update of Holocaust.
And Grindhouse has played the film in theaters as recently as June! Here's the rerelease trailer, cut in a Blair Witch style, but I gotta warn you—even though it's on YouTube, it's still pretty nasty.