Metabolic Effects of Endogenous Bile Acids After Gastric Bypass Surgery

Colesevelam is an approved drug with well known adverse events. Gastrointestinal side effects (Obstipation, flatulence, abdominal pain, diarrhea, nausea, meteorism, vomiting, chanced faeces) are very common (\>10%) or common (1-10%), but are mild and tolerable in most cases. All participants will be monitored closely, and colesevelam will be discontinued if the subject experience unreserved adverse events. All effects of colesevelam are transient (17-19) as the compound is not absorbed to the systemic circulation, i.e. treatment effects cease when the drug is excreted from the intestine. Specifically, no permanent metabolic effects of colesevelam has been observed in crossover experiments (27). Therefore, 8 weeks of colesevelam treatment as planned in the current study will have no long lasting positive or negative effects on the participants.