IBS can in fact become IBD, there are medical studies on this. You might need further tests to rule this possibility out. IBS is a name given to symptoms with no underlying pathology and the diet for IBS high fibre is the opposite of the low fibre for people in active flare from crohns. I have IBS and IBD, the IBD came first. I have found avoiding gluten helpful. I hope you get to the bottom of this soon.