- Subjects with a pre-existing condition interfering with normal gastrointestinal anatomy or motility, and/or hepatic function that could interfere with the absorption, metabolism, and/or excretion of the study drugs. Examples of conditions that could interfere with normal gastrointestinal anatomy or motility include cholecystectomy, gastrointestinal bypass surgery, partial or total gastrectomy, small bowel resection, vagotomy, malabsorption, Crohn's disease, ulcerative colitis, or celiac sprue. Examples of conditions that could interfere with hepatic function include Gilberts syndrome.