Belly,

I'm not quie sure what you're asking but I'll take a stab at answering it.

Coarse food could be high fiber foods that are harder to digest like whole wheat, whole grains, fruits, vegetables, legumes, and nuts. If your gut is irritated these foods can act like sand paper and make the gut more inflamed and prone to symptoms like diarrhea, and bleeding. 

For people with IBD foods like these can cause problems when we are in a flare-up. When flaring we tend to need to eat what I call "food without edges," or more easily digestible foods like yogurt, white rice, white bread, baked chicken, baked white fish, and eggs.

Hope this was helpful. If not, please give a few more details and I'll try again.

Cheers,

Elizabeth