Well, have you heard of Amnesia: The Dark Descent?
Now that is a game that doubles as an extremely powerful laxative.
Amnesia focuses on tension, atmosphere and effects to make you increasingly nervous and just terrified by the anticipation. So when you DO see a monster, you WILL shit whole chimneys.
Outlast, on the other hand, relies on some atmosphere, like fog, for example, where you're lucky if you can see a few feet ahead, but it's mostly blood and a few jumpscares (Most aren't too bad). It's not the first game I would recommend watching someone play, and it's certainly not the first horror game I would recommend playing, but it's much less scary when you're not the player, so I think you can handle it.
