Have you heard of FODMAPs diet? My Tdoc recommended it to me. It does have some carbs in it. The idea is that IBS is linked to mood and doing this diet intermittently when IBS is bad can help mood too. It's pretty restrictive, but brief. Then you return to your "normal" eating. I haven't tried it yet.

https://www.psychologytoday.com/blog...fect-your-mood