I'm an RN in the recovery room of a level I trauma center - so I literally see EVERYTHING.
When I was in nursing school, the smell of poop really bothered me - so during the Summer, I worked as an aide at a nursing home and believe me that TOTALLY desensitized me to the smell of poop, pee, etc.!!!
I absolutely love being an RN - there are a million different things you can do in our field. I personally love bedside nursing. If you don't like the job your doing, you can always transfer to another unit. Even after many years, you still learn new things everyday!!
Good Luck and don't worry so much about it - it'll all fall into place.