I recently had my IUD removed b/c it was doing mad things with my cycle and my sex life.  I decided to go back on the pill, as my husband and I are still a few years out from wanting to have children.  However, I've recently embarked on my quest to become vegan, and paranoid as I am, started to wonder if there is a significantly increased amount of fiber associated with the vegan diet that would make my birth control pill pass through my body without fully absorbing.  I've heard of this happening with other pills/vitamins...but am not sure if there is something special about the pill.

Simple question: can eating vegan/macrobiotic inhibit or interfere with the effectiveness of a birth control pill?

no!  it should not affect your in that way - but taking the pill can affect the absorption of certain vitamins/minerals  - so your larger concern should be making sure that you are getting the nutrition you need

http://www.virginiahopkinstestkits.com/everywomanbc.html

scroll down in that link to the section on vitamin deficiency and drugs, it talks about the pill lowering levels of folic acid and B6 and suggested supplementation to help counter-balance that.

Thanks Ann.  I've spent the last 10 years of my life reading and absorbing everything I could from health and fitness magazines.  I thought I'd become a sort of defacto expert on things...but now as I venture into this world of veganism, I'm finding myself with all sorts of questions...relearning and transforming!