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What is Appendicitis?

Appendicitis is inflammation of the inner lining (lumen) of the vermiform appendix that spreads to its other parts.  Obstruction of the appendiceal lumen is the primary cause of appendicitis.  Appendicitis may occur for several reasons:  a build-up of fecaliths (rock-like stool), the swelling of lymphatic tissue, gastrointestinal viral infection, foreign materials, parasites, and/or a genetic predisposition.

The obstruction triggers a build-up of bacteria, which attack the wall of the appendix, leading to the accumulation of white blood cells and the formation of pus.

If the inflammation and infection spread through the wall of the appendix, the appendix can rupture. After rupture, infection can spread throughout the abdomen; however, it usually is confined to a small area surrounding the appendix (forming a peri-appendiceal abscess).