If you can stand the smell of melena every day, then GI is for you.
Don't let competitiveness of the fellowship color the decision of what you want to do.
GI is a great field, and it has a lot of overlap with general medicine, so it's a good fit if you want to do a lot of procedures but still have chronic patients and have to do a lot of detective work. In private practice, it may be possible to do both GI and hepatology. In GI you have to know a lot about cancer, palliative care, nutrition, anemia, infectious diseases, and tidbits of several other medical subspecialties. Plus, you will have close relationships with surgeons, especially if you take care of any post-transplant patients.
However, like the previous poster said, GI is dividing more and more into proceduralists and nonproceduralists. In my residency program, we have few GI docs who do nothing but ERCPs and rarely ever round. I can see the benefits of that lifestyle (no clinic, no chronic patients of your own, more money).