the most common explanation is that the appendix is a vestigial structure with no absolute purpose. in The Story of Evolution, Joseph McCabe once argued:

the vermiform appendage—in which some recent medical writers have vainly endeavoured to find a utility—is the shrunken remainder of a large and normal intestine of a remote ancestor. this interpretation of it would stand even if it were found to have a certain use in the human body. vestigial organs are sometimes pressed into a secondary use when their original function has been lost.

given the appendix's propensity to cause death via infection, and the seemingly perfect health of those who have had their appendix removed, the biological purpose of the appendix has mystified scientists for some time. there have been cases of people who have been found, to have a congenital absence of an appendix. there have been no reports of impaired immune or gastrointestinal function in these people.


defecation is the final act of digestion by which organisms eliminate solid, semisolid or liquid waste material from the digestive tract via the anus. when humans expel feaces, waves of muscular contraction known as peristalsis in the walls of the colon move fecal matter through the digestive tract towards the rectum. undigested food may also be expelled this way. this process is called egestion.

information is taken from:
http://en.wikipedia.org/wiki/Vermiform_appendix
http://en.wikipedia.org/wiki/Defecation