Hard time trying to change specialty

I'm trying to change specialty and find a job in the gastro field. My previous and only experience was in NICU for 1 year in a hospital in Atlanta. It was my first job but I got so stressed that I decided to change specialty. I spent a day in a GI lab during College and I liked the environment. I think I will enjoy working in a GI lab, but the jobs available are for nurses with previous experience. Is there any GI training program in the Atlanta area?How did these GI nurses get experience in the field?