I think healthcare is unique in one way: it relies on teamwork. True teamwork, every single day in every single moment. The biggest problem where I work is "department wars." They complain about us; we complain about them; management has to resolve it somehow.
When I worked in corporate America, teamwork was needed sometimes, and other times it wasn't. There were some projects done in complete isolation from other disciplines. On those projects where true teamwork was needed, i.e. a multi-step process where multiple departments had a hand in making it work, and work product flowed from one department to another, that's where it got ugly.
I really do think it's the nature of the beast. Work product flows from one nurse to another, from one department to another, every single day, every single shift. Conflict is bound to happen, and we will always run into those that can't rein in their negative thoughts to ensure that whatever they are thinking comes out of their mouths as constructive criticism.
Only one co-worker I have could be truly categorized as a bully. And people don't like her much.
Then, again, some things can be misunderstood. I have one coworker that says whatever she is thinking at any given time to anyone. Some of what comes out of her mouth has a bite to it. When I first met her, I thought, "Whoa. You hungry or something?" Then, after a time, I realized it's just the way she is because she has the same bite whether talking about work, non-work life, food, travel, nearly anything. She's very opinionated, and it can easily be misconstrued as "eating co-workers" if you haven't been around her.