Tanya,
I have Crohn's and am anemic, have always had trouble with it. Last November I had a total blockage and had surgery. During surgery I had a blood transfusion which was due to anemia. So about two months ago I had my first IV iron injection which took about 4 and a half hours. You get some Benadryl first and a small test dose then if you do fine they proceed with injection. Afterwards I was a bit tired and I was achy for a few days later. It took a few weeks to notice a difference but it did help. The doctor said I would probably need another in a year, we will see. Good luck with your injection and don't worry about it, compared to all the other things we go through its a piece of cake!