why bran is bad for ibs

It is best to remove all cereal bran including oat bran of from your diet at least to start with. The IBS research shows that insoluble fiber from cereal bran can exacerbate IBS symptoms in many individuals.

You might be able to add small amounts of oat bran back in later because it is unique contains some soluble fiber. I cannot eat oat bran at all but I can handle regular oatmeal which has most of the bran removed.