Jacob's Ladder (1990)

Post-traumatic stress disorder manifests in many forms, among the harshest of which is visited upon the Vietnam War vet who must climb up from the depths of a living hell in Jacob’s Ladder (1990). Hitting the dirt every time a car backfires and taking Asian fast-food deliverymen hostage are child’s play compared with the open-eyed nightmare entrapping Jacob Singer (Tim Robbins). The New York City mailman gallantly shrugs off flashbacks to his first marriage, but the horned creatures that attempt to slay him in the subway are not so easily put aside.

Speaking of flashbacks, Tim Robbins gets plenty of opportunity to flash his back in the bathroom. First when he steps into a hot shower, and later when he's forced into an icy bath. He'll make you want to scrub-a-dub-dub!