The cause of appendicitis isn't known. There are several theories. It may be caused by a blockage, which makes pressure rise inside the appendix and makes inflammation more likely. Possible causes for the obstruction:constipation; cancer of the caecum(where the large intestine and the small intestine join); a condition in which normal cells that resemble lymph tissue grow rapidly(known as lymphoid hyperplasia); simply diet-studies show that appendicitis may be less common in people with high-fibre diets.
Attribution: BUPA