I'm new at this, but I have just diagnosed myself :) with moderate IBS-D. I also have PCOS (Polycystic ovarian syndrome), and I am finding more and more that there is a link between the two, although there seems to be little research to prove it. Here is why this is relevant to your post: PCOS has caused me to go for months, up to a year and a half, without periods in the past (I am 26, and didn't start menstruating until I was 16.) I have always had irregular periods, but only in the last two years have I had the painful gut episodes that end in diarrhea, always early in the morning. More and more I am putting together that the disfunctions in my body are related, and I am starting up a very strict no-milk, no-gluten, low-fat diet, in hopes that the episodes will stop. I would be interested in any studies that may link infertility/irregular periods with irritable bowels, because anecdotally, I am finding all kinds of posts on the internet about people who have both.