Last year I had started working on the ID team of a large corporation, and within a few weeks I knew it wasn’t a good fit for me. The team did not really know how to utilize me, and all the other team members were too senior for me to relate to and too jaded for me to learn from.
I was very unhappy with my situation, and after 6 weeks told my manager I wanted to leave. I was very professional in explaining honestly that I felt it was not a good fit and me continuing to work there would be a waste of my time and theirs. He was very understanding, did not get upset or question my decision, and I gave him honest feedback that alerted him that his team was not conducive to attracting young new talent. Granted, he was a really calm and collected guy overall but if you think you going to a new job will make you much happier and be better for your career you should do it, and if you do it right you can avoid burning bridges. It does kind of depend on the size of the company too. A huge company can afford to recruit someone new. A smaller team might have trouble replacing you, and the extra workload passed onto your coworkers may cause some resentment.
In the end, do what’s right for you and be honest. I’m much happier with my job now, and have never regretted that decision.