I suffer from chronis constipation and it was my naturopath who took me off of the materna. She put me on chewable vitamin b12 with folic acid and has me taking one full scoop of greens with it. I've been doing this for 2 weeks and my body is finally loosing the bloat. Like some have said here, go to a vitamin store and they should have some good brands and options without the iron. I feel your pain though. I wanted to screem when I found out my doctor recommended it knowing my issues. I never even thought that the iron in the pills was putting me into so much pain. GL