Complications of Appendicitis

The most serious complication of appendicitis is rupture. The appendix bursts or tears if appendicitis is not diagnosed quickly and goes untreated. Infants, young children, and older adults are at highest risk. A ruptured appendix can lead to peritonitis and abscess. Peritonitis is a dangerous infection that happens when bacteria and other contents of the torn appendix leak into the abdomen. In people with appendicitis, an abscess usually takes the form of a swollen mass filled with fluid and bacteria. In a few patients, complications of appendicitis can lead to organ failure and death.

source: http://digestive.niddk.nih.gov/ddiseases/pubs/appendicitis/index.htm