A patient who has recently undergone colonoscopy and esophagogastroduodenoscopy (EGD) for rectal bleeding with 100s of polyps found within the colon and the rectum relatively spared (10 diminutive adenomatous polyps) was also noted to have several diminutive duodenal polyps on EGD, none with high grade dysplasia. Which of the folliowing is the recommended chemoprophylaxis for ths patient?