The appendix is a true diverticulum of the cecum, its base originating at the confluence of the teania coli. The appendix is relatively large at birth and progressively decreases in size until age 5 years. Its position with regard to the cecum can be variable and this explains its many potential presentations when inflammation occurs.
Variable presentations are also common in the extremes of age.
Acute appendicitis is the most common surgical disease of the abdomen. The goal of therapy is rapid diagnosis and treatment before rupture. Between 6 and 20 percent of the population develop acute appendicitis during their lifetime. By definition, the pathologic finding in acute appendicitis is mucosal disruption with invasive infection and inflammation. The invasive organisms, consistent with normal stool flora, include E. Coli, Klebsiella, and Enterobacter.