Iodine, progesterone and constipation

A while back I commented that Iodine constipated me and I had to be vigilant to keep my bowels open. Everyone said no, that they had the opposite experience. Well, for the last couple of weeks there are several on the yahoo forum that have complained that Iodine constipated them too, and I am especially interested in your comments to this:

"I've read that Iodine increases progesterone levels. High progesterone
is known to cause constipation, it affects the parasympathetic system."

Anyone heard about this, or know if it is true? Tweet