Now that I'm back for a brief visit to the US, here are a couple quick responses to some issues on this thread.
In terms of pedi GI, it is a great specialty for those interested in research or clinical care. The diseases they see a lot of, things like reflux and cholestasis and, for those with a nutrition interest, obesity, seem to be becoming more common - or at least more often referred to GI specialists. The top few fellowships are competitive (quite competitive), but many excellent programs are less competitive. I am pretty sure that job offers are plentiful now for grads of pedi GI fellowships.
In terms of the stress of neonatology, I think it is consistent with that of any other intensive care specialty. There are moments of high tension and drama, which often occur in the middle of the night, and there are the more usual quieter times focused on the details of patient management. Parent interactions can be fun and rewarding for families who have babies who do well, and of course, very difficult in other cases. The key to managing the stress is how you balance your time, and of course, the experience you get allowing you to understand how to respond to the inevitable crisis situations that occur.
There are many top neo fellowships that have H1 and J1 Visa holders.
As always, I defer to others regarding salary and "best program" type of questions!
Regards
OBP