Trial to Understand Efficacy of Colesevelam in Diarrhea Predominant IBS Patients With Bile Acid Malabsorption

Colesevelam (Welchol) is approved by the Food and Drug Administration (FDA) for the treatment of high blood cholesterol levels and to treat type 2 diabetes however, Colesevelam is not approved for the use proposed in this study and is considered investigational.

A placebo looks exactly like the study drug, but it contains no active ingredient. This is used to learn if the effects seen in research participants are truly from the study drug.