Appendix is a vestigial organ in human being, attached to right colon.
The appendix produces a bacteria destroying protein called immunoglobulins which help fight infection in the body. Its function, however, is not essential. People who have had appendectomies do not have an increased risk toward infection. Other organs in the body take over this function once the appendix has been removed.
Appendicitis (infection of appendix) occurs when the appendix becomes blocked, often by stool or as a result of infection in body, since the appendix swells in response to any infection in the body. In elderly person, it may be blocked by tumor, thus requiring proper evaluation before going for surgery.