The medical education system is really quite twisted: We spend a mere 2-12 weeks exposed to a specialty and then must make a quick decision as to whether we want to spend the rest of our careers in it.
A few recommendations:
1) Understand that what you are seeing in your rotation may not jive with what you would really be doing on a day-to-day basis after training. For example, most internists don't spend the majority of their days in the hospital, although you will likely do that on your internal medicine rotation.
2) Ask attendings what they do and don't like about their fields. Make sure you could stomach the worst parts.
3) Consider whether you like the operating room or not.
4) Shadow a few attendings outside of rotations.
5) Study statistics on physician burnout by field.
6) Finally, do some soul searching, and don't be afraid to be honest with yourself about your likes and dislikes. It's okay to admit you want a reasonable lifestyle or a salary that could support a large family. Considering those "ugly" issues now may help you avoid a lot of pain later.
