I’m looking for a horror movie I saw a long time ago (definitely older than 2010). Four people — two couples — went on a trip. They stopped at a gas station or a small store in an isolated area, and from there everything went wrong. There were brothers living in that area who were hiding a dark secret.

One of the brothers was like an animal — either deformed or mentally unstable — and he killed people. There was also a pregnant woman being held captive, and her tongue was cut out. She ended up killing herself after being freed. At the beginning, one of the group had a camera and was filming, but this was NOT a found-footage movie.

There was a scene in an open field where one of the girls was running and got killed — her intestines were visible. In the end, it seemed like one girl would survive, but she tried to save her boyfriend and got killed in a car.

There was tension between the couples — I think they found out someone had cheated. Most of the movie took place in that rural shack or gas station. The killers were like hillbillies, not modern or high-tech. Not The Butcher, not Wrong Turn, not Rest Stop, not Storm Warning. Please help!