<prompt> Most common initiating factor in acute appendicitis is:Luminal obstructionBacterial infectionLymphoid hyperplasiaPerforation  <response>: Ans. a Luminal obstructionRef: Sabiston 19th edition, Pages 1279-1282 Most common cause of acute appendicitis -- Obstruction Most common cause of Obstruction -- Appendicolith Fecolith -- 15 can be seen on plain X-ray itself Others: Lymphoid hyperplasia, vegetable matters, seeds, parasites, neoplasm. 