I've had a lot of bouts of it over the last 7-ish years (I've had undiagnosed ME/CFS for 10 years).
Please, please make sure that not only are you drinking a lot of water (which I was good about) that you also consider getting electrolyte support as well (I did poorly on that side and now have lots of issues related to potassium and magnesium deficiencies).
That said? It's a bit better now. I seem to be able to track my episodes with either a food trigger or my menstrual cycle. I haven't done the full elimination diet and sometimes I sneak a tiny bit of something that I know I can't tolerate in a regular serving size... sometimes I can get away with a tiny bit, sometimes I sneak a bit more and pay the penalty.
Right now things I know will trigger it - gluten, dairy, fried or high fat foods; again, a tiny nibble seems ok - but I am not always good about it and sometimes I eat more than I should. I can always tell within 20 minutes and it seems like 5-6 trips to the bathroom within an hour or two are my penalties.
I don't know if there is a placebo effect, but it *seems* like there are times where I am in the middle of an episode and I apply a heating pad to my lower back that it slows it down and/or shuts it down. Again, it might be in my head... but I start applying heat now after my second trip to the bathroom with a loose stool and typically I think I have fewer trips afterwards. If it's not really helping slow it down, at least it seems to ease some of the cramping when I have it.