I have IBS and have been doing Low carb for about 2 1/2 weeks. I had a lot more diarrhea than usual the first week, but it wasn't accompanied by cramping or pain. Then my system started to get back to normal, well normal for us with IBS. I now have the usual where I am backed up for a few days, then have diarrhea, and so on. Your weight loss tends to stall during the "backed up" days, but it will pick up again once you go. I do notice that after I eat dinner now, I don't have to rush to the bathroom like I used to have to do. I really think the Low carb diet helps a little with IBS.