I am trying to find the title of horror film that has a scene with a woman in the shower undergoing a transformation into a demonic pig-being. I remember being traumatized by it, because she was pulling red sinewy guts out of her mouth as she changed. I saw this at a friend's house around the same time Silent Night, Deadly Night was new to VHS which would put it around '85 or '86. I would definitely appreciate any help identifying this flick. Thanks
CH