Try introducing green veggies. Only small amounts combined with other healthy foods. I lost 121lbs in 18 months with a mostly IBS-D (occasional IBS-C now, used to always be IBS-C) issue. I did some fasting by drinking 3 full glasses of warm tea before eating anything, also tried to remain active... Anytime I would normally sit, some tummy exercises, and I eliminated dairy and unhealthy foods without depriving myself of them (if I want pasta, I'll have 1 small bowl and no heavy carbs for 2-3 days following). Those things worked for me.... you can lose weight just got to find the way your body likes best and eventually your body will adjust. My problem now is unhealthy foods run thru me same as dairy. Pastas, bread, and certain dairy cause me the IBS-C side.