I was also prescribed Ferrograd C, but I found it a bit hard on my tummy. So now I take the iron biocomplex by "nutri-medicine", which is available at a naturopath or health food store. It includes vitamin c (to aid absorbtion) and folate. I haven't had any problem with constipation with them at all (even while taking three times a day).

The other one I've heard people recommend is Flurodix (Sp?) which is a powder you dissolve in water and is available at the chemist - apparently its also easier on the tummy.

Remember to take your iron tablets away from tea and coffee though, because these inhibit your absorbtion.

HTH