Can blue dye cause diarrhea?

I had my baby shower last Saturday and I'm 37 weeks, but at my shower we had blue velvet cupcakes and ever since around that time I've been having upset stomachs and loose stools. Now it has turned in to diarrhea. Some have the bright green color which I'm assuming is from the blue color. I've been eating a cupcake a day since then. Yesterday was the only the day it wasn't colored, but still was loose stools. Reaction to the dye or??