Prenatal vitamins and IBS

This may be a long shot, but here it goes.  I have fibromyalgia and IBS. I tried about 4 different brands of prenatal vitamins. All Made my IBS act up bad. I was told to try two Flintstone vitamins instead. Still seems to be causing a flare up. Major bloating and constipation. I take a probiotic, but still IBS is acting up. Anyone have anything that was suggested to you that you try for prenatals? 😊💜