

fiber supplements
Fiber supplements are usually functionally useless (e.g. study https://pmc.ncbi.nlm.nih.gov/articles/PMC5413815/ ) - and that includes inulin - or even harmful. Unless of course if by “supplements” you mean something like “I eat raw XXX as a fiber supplement”.

And if you were to read the study beyond the title, you’d notice they list psyllium husk as working, making it fall into category I wrote as
There exist psyllium processed supplements. If you were to switch to them, they don’t gel (which is likely what helps your for the IBS), and within 6 months or so you’d be back to being fucked.
I literally wrote “e g. study”. So you can take that attitude and shove it.