 The identifiable landmarks in the cecum are the appendiceal orifice—which is a curvilinear indent indicating the location of the appendix from the lumen of the bowel, and the ileocecal valve, which appears as a puckering in the most distal fold of the cecum.The bow and arrow sign uses the curve of the appendiceal orifice to point toward the direction of the ileocecal valve, as if it were a bow guiding an arrow.The colonoscope can be passed in this direction in order to enter the terminal ileum.