Which of the following statements about familial adenomatous polyposis (FAP) is/are true?

C. Appropriate surgical therapy includes total abdominal colectomy with ileorectal anastomosis and ileoanal pull-through with rectal mucosectomy.

DISCUSSION: The genetic defect is of high penetrance: nearly all affected patients develop hundreds to thousands of polyps. By definition, at least 100 polyps must be present. Recent studies have shown that even patients with the identical point mutation can exhibit variability in the phenotypic expression, suggesting that environmental or other genetic factors play a significant role. The phenotypic variations concern age at onset, size of polyps, density of polyps, and extracolonic manifestations of the disease. Although panproctocolectomy with ileostomy is not well-accepted by patients because of the stoma, acceptable surgical options include panproctocolectomy with ileostomy, total colectomy with ileorectal anastomosis, and ileoanal anastomosis with rectal mucosectomy. No pharmacologic agents have been demonstrated to be efficacious in this condition, though several have been tried.