Hi Katie, I used to have this, not all the time but often.  i found it helped to stay very consistently hydrated.  it was worsened by eating, too, so I got pretty thing. I totally hear you. It'll occassionally happen to me but it is very rare now, and I'd say it decreased during the first year of treatment and really improved between year 1 and 2.  I found that it gradually decreased in intensity, length and frequency.  Sorry you're struggling with it but please know it can improve. 

I've been in treatment a long time now (4.5 years) and it has been a real rollercoaster ride.  I improved steadily but slowly for 2.5 years, was eating off list 4 and then hit a huge bump in the road, probably an infection, followed by prolonged inflammation.  Then I dropped back to only tolerating about 5 things on list 1. At this point, I don't eat any grains/starches and am eating some things on list 4 right now.  But I'd say I steadily eat off list 3, though not everything on the list. 

It's very tricky to find the right balance.  I still struggle with it and when I get very symptomatic, my inclination is to limit the foods I eat.  Don't know if that's a good response or not, but it sometimes becomes a way to try and help the situation.  So I totally get it. 

Good luck and stay hydrated!  I wish I had more helpful tips.  I guess to make sure whatever water you're drinking really agrees with you.