How exactly does appendicitis occur?

Unknown: Appendicitis is the development of an infection in the appendix, a small pouch attached to the beginning of the colon. It is unknown why this occurs. Treatment is surgical removal of the appendix.

Variable: The appendix is an appendage of the intestine. The most common cause is obstruction. This can occur secondary to a fecalith (hard pellet of stool) of swelling of the lymphoid tissue that lines the appendix. This makes appendicitis more common in children prone to constipation or gastroenteritis.