The cause of acute appendicitis is primarily bacterial infection of the appendiceal lumen due to various reasons. The appendix itself is a narrow tube connected to the cecum. If a fecalith falls into the lumen, it can cause obstruction of the appendiceal lumen, leading to an increase in intra-luminal pressure and circulatory disturbances in the appendiceal wall. At this time, the mucosa is susceptible to damage, and bacterial invasion of the wall can cause infections of varying degrees. Additionally, gastrointestinal dysfunction, such as diarrhea or constipation, can also cause spasms of the appendiceal vessels, leading to blood supply disturbances and resulting in acute inflammation.