IBS-D how to ease the bloating, abdominal pain, nausea, and fatigue?

My grandson was diagnosed with Crohn's in his junior year of college. That was during covid so he spent his senior year doing home classes. His is extremely bad. Usually it effects one part of the intestine but his is throughout. He has had about 4 flairs since being diagnosed and has ended up in the hospital for at least a week at a time. My point though is he never had any symptoms before the first attack so it's really a good idea to have this researched further.

Hi, I have that issue. I have Crohn’s and I’ve had my ileocecal valve removed along with 18” colon. My intestines move along like the Indy 500! I don’t want to take antidepressants, or be doped up just so I can sort of function.
I take Imodium every day but if I eat low fat, very low fiber and avoid nitrates, nitrites and other know preservative triggers, then I can skip a day of taking Imodium. I still prefer to stay home just in case my intestines have made plans of their own.
This all started in 1986, several months after the birth of my daughter in 1985.
It’s been a lot of trial and error. Fiber supplements tear my stomach up. So the “eat more fiber” cure all is not for me. Everyone is different so treat yourself as that.,don’t let anyone put you in a box.
My new GI looked at my novel aka chart and said to me that Imodium is the only thing I can physically handle since I’ve tried it all. You have to be your own advocate, after all drs are not miracle workers. They are continuing to learn and that’s a good thing.
I started including an amino acid, L-Glutamine, daily on an empty stomach. It’s not a cure but it seems to help. It doesn’t give me a license to eat whatever, but between avoiding the nitrates and nitrites and processed foods as a whole, I don’t have the pin prick sensation through my stomach.

Sorry about the length of this but I’m just relating my experience. I wish you well in your journey of finding relief.