You are evaluating a 29 year old physician for constipation. Her physical examinationincluding ano-rectal exam is normal. Thyroid testing and serum calcium levels are
normal. A colonoscopy is normal. You make a diagnosis of constipation-predominant
irritable bowel syndrome. The patient has minimal response to bulk forming agents and
osmotic laxatives. You recommend beginning tegaserod. The patient asks how this drug
works.
Which of the following is the best description of the mechanism of action of tegaserod?
