If you go to ...org (or is it .com?), you will see that Heather, who is a well-known IBS expert, says that insoluable fiber is bad for all kinds of IBS. I've found that eating Fiber One cereal and other stuff like that do make me feel worse -- definitely had that "stuck" feeling. Just eat lots of brown rice, fruits, and vegetables for your fiber, and you will probably feel better. Also, drink tons of water!! And be careful with high-fiber cereal especially. I wasn't measuring my dose, and when I finally did measure, it turns out I was getting over 100% of my fiber just from the cereal -- there was just too much in there for me to not be bloated. And I always felt really full! So eat a lot of fiber, but don't go overboard!