I have been given IVIg. The medication is Gammunex C in my case. I have received it perhaps 10 times. Frankly, I don't see a difference, or a very subtle one, at that, but my neurologist does. I have had no side effects and was told it will not give me a stroke, by some expert. I received it (and continue to)as an out-patient in a hospital. Each infusion takes about 6 hours because I am given 25 grams. My CA was deemed to be auto-immune related. I live in Israel. The product I used was made in the USA by an outfit called "Tanchris" I think. Good luck. It doesn't hurt beyond the initial prick. Here, you can unplug the pump (a battery kicks in) and go to the bathroom if necessary and sit in your armchair (has a foot rest) and read or watch TV. It's quite relaxing.
One more thing: I also had plasmapheresis (cleaning of the blood). I dont know what the word "flush" means in this case. Also I just noticed, the way it is administered is different. My infusions are once per month.