I developed IBS and anxiety together a couple of years ago. Mine is a constant issue. You do want to make sure to drink fluids, but that really hasn't helped me. I feel better and have bowel movements when I am in a quiet place and am resting. I have also noticed a connection to my thoughts. I think that my brain is in hyper drive, causing anxiety and IBS. I'm about to go to the dr to see about some meds. My sister has the same issue and she just went on Zoloft and said that it helps a lot. Good luck.
P.S. I get relief from relaxing youtube videos and from watching slow, relaxing nature shows etc.