Cholecystitis causes

Causes
Cholecystitis is often caused by cholelithiasis (the presence of choleliths, or gallstones, in the gallbladder), with choleliths most commonly blocking the cystic duct directly. This leads to to inspissation of bile, bile stasis, and secondary infection by gut organisms, predominantly E coli and Bacteroides species.

The gallbladder's wall becomes inflamed. Extreme cases may result in necrosis and rupture. Inflammation often spreads to its outer covering, thus irritating surrounding structures such as the diaphragm and bowel.

Less commonly, in debilitated and trauma patients, the gallbladder may become inflamed and infected in the absence of cholelithiasis, and is known as acute acalculous cholecystitis.

Stones in the gallbladder may not cause obstruction and the accompanying acute attack. The patient might develop a chronic, low-level inflammation which leads to a chronic cholecystitis, where the gallbladder is fibrotic and calcified.