Which of the following statements about surgical anatomy of the colon and rectum is/are correct?

B. The rectosigmoid junction is situated at approximately 15 to 18 cm. from the anus.

E. The arterial arcade created by communicating vessels at 1 to 2 cm. from the mesenteric is called the artery of Drummond.

DISCUSSION: The cecum has, indeed, the largest inner diameter of all segments of the colon; however it usually measures between 7 and 9 cm. In patients with a distal obstruction and a continent ileocecal valve the cecum dilates. A diameter of 13 cm. or more is considered at high risk of perforation, and therefore surgery is often needed. The rectosigmoid junction is situated approximately 15 to 18 cm. from the anus, which places lesions in the sigmoid colon within reach of a rigid sigmoidoscope. The rectum is covered by peritoneum only in the anterior and superior aspect. The remainder of the rectum, or most of it, is extraperitoneal. The ileocolic, right colic, and middle colic arteries are branches from the superior mesenteric artery and supply blood to the ascending colon and the right half of the transverse colon. The artery of Drummond is an arcade that runs 1 to 2 cm. from the mesenteric border of the entire colon and provides communication between the superior mesenteric and inferior mesenteric arteries.