An 83-year-old female presents to the office complaining of diarrhea for several days. She explains she has even had fecal incontinence one time. She describes loose stools 3–4 times a day for several weeks and denies fever, chills, pain, recent antibiotic use. The history suggests that the patient has: A 58-year-old man is diagnosed with Barrett’s esophagus after an endoscopy. He has no known allergies. Which of the following medications is MOST appropriate to treat this patient’s disord...