Creepy... and really gross

I listened to this book on audio, and while I didn't find it scary, it was definitely bloody and gory in a slasher film kind of way.
Sara and Martin are guardians to six difficult, troubled, teenagers. They take them camping on an island that is supposedly deserted. But, surprise, the island is home to a doctor and his vicious creations. And they have no way to get off the island. These are city kids, and they are easily spooked, but we find out they have a good reason. The island is crawling with cannibals and worse...
The cannibals are scary, but also a bit silly - some of them carry forks and knives, and even salt shakers. So...
There are a few twists I didn't expect, and they were quite clever. But, the gross-out parts were a bit much for me.
This book was ok for me, but if you are a gore/slasher fan, then you will enjoy this one.