ibs4dIBS-D Diet Guide Key Takeaways. The IBS-D and Food Connection: Diet plays a crucial role in managing IBS-D. FODMAPs (fermentable olosaccharides, disaccharides, monosaccharides,IBS that causes increased diarrhea is often called IBS-D. If you have IBS-D, you have belly pain and other IBS symptoms plus frequent bowel movements. Your stool mht be