T.F.
I've been anemic most of my life. In my case, I have too much iron (almost to the point of toxic)...it is an absorbancy issue and I am on liquid B-12.
At times, especially during pregnancy, I had B-12 injections regularly.
I bruise if you look at me....that part is not fun because I'm always walking around with some bruise.
I realize you went to the ER. It is important to follow up with your regular Dr who knows you to get more test and be monitored closely. I routinely have complete blood counts and I also go to Medical City to the Cancer center to be monitored there as well. The blood Dr's are supposedly very good so I go see them. At one point it was thought that I had leukemia but thankfully that was not the case. My body does not absorb nutrients the way it is supposed to.
I don't know anything related to gastric bypass as the only time I have weighed over 116 was when I was pregnant and I think I was a whopping 135 at that time.
Good luck..