IBS questions

I have severe IBS. Lately, I've been waking up around 3:30 or 4:30 feeling very nauseous, with severe bouts of diarrhea and occasional vomiting. I was wondering if anyone else has this? It's like getting the stomach flu every week and I can't figure out what it is. It has been happening since January. I tried changing my diet and exercising more and taking a probiotic. Nothing seems to calm down my digestive tract. The only other thing I can think of is it being subconscious anxiety related since it wakes me from sound sleep? Anyone have any ideas about this or know a good solution for IBS related chronic diarrhea and nausea/vomiting?