Definition of Appendix Appendix, also called vermiform appendix and abdominal tonsils is a work-like diverticulum which originates from posteromedial wall of caecum. Location of Appendix Appendix lies 2 cm below the ileocaecal orifice. It is located in the right iliac fossa. The appendicular orifice is marked on the surface by a point situated 2 cm below the junction of transtubercular plane and right lateral plane. The base of appendix is fixed but the tip of appendix is directed differently. There are 7 positions of tip of appendix: Retrocolic, Pre-ileal/Post-ileal, Promonteric, Pelvic, Mid-inguinal and Paracolic position. Mesoappendix or appendicular mesentery suspends appendix into the peritoneum.