Vamplady - couldn't tell you specifically cos I'm not on any medication - have never been prescribed any and I've had IBS for over 10 years - however, my BM colours are like an ever-changing rainbow - pale brown, greenish, two tone - you name it. But seriously, as long as its not streaked with blood, or very claylike (which I think could indicate a liver disfunction but don't quote me cos I'm not medical) - I think a range is fairly normal, as is a range in consistency. I would also guess that, like a change in diet etc, surely a change in medication might very well precipitate a change in BM.Good luckSue