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-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,