Read about 3 - 4 years ago - Dystopian/Horro

[Blair]

Ages around teen and pre teen get sucked into an alternate dimension where they have to survive in a hostile environment for a certain amount of time to be spit back out into our world. I think the cover was mostly red and black with I think either a red eye or a red circle around the title.

[Corinne]

Maybe it's the Midnighter's trilogy ?

[Sycorax]

Displaced Person, perhaps? I imagine there are a lot of books with this premise though.