GI is definitely one of the best IM subspecialties and there are many reasons to be positive on the outlook, but this comment is definitely not accurate. The reason it is unreal... is because it is not real. None of the private guys I know are not working 40 hrs to make 700, they are working more hours for much less than this, and much of it (like everyone) is uncompensated- path letters, patient messages/ calls etc. For most in academics it is less than half that. Could you make 700? Yes, 8?9? 1 mil+? Yes, there are folks out there doing it, and working accordingly. 40 might be what you do on paper- and of course anyone who says 40 automatically means no call. There are hospitalists who take extra shifts in their off weeks and make more than gastroenterologists, and still end up with 4 times the amount of vacation- so many ways to look at this. However, the point is well taken, GI is amongst the better compensated and in the right setup you can find reasonable work-life balance. The threats to the profession have been discussed here multiple times but should not dissuade anyone.
However, anyone who thinks GI doesn't have emergencies that need immediate intervention is wholly uninformed and should be dissuaded. There are plenty of all outpatient/ no-call jobs out there, if that's what you end up choosing to do (definitely less fun though)