Cholecystitis is an inflammation of the gall-bladder. It is commonly due to gall-stones within, but may be due to infection from without, particularly in typhoid fever. When gall-stones are present the cystic duct is obstructed, the bile is unable to escape, and the gall-bladder becomes distended. The coloring-matter of the bile may eventually be absorbed and the bladder be filled with a colorless fluid. From the pressure of gall-stones ulcers may form and perforation into the peritoneal cavity, into the intestine, or through the abdominal wall occur.

In the acute catarrhal type the gall-bladder is distended and tense. The walls swollen, edematous and softened. The 28 mucosa congested and covered by mucous. The peritoneal covering may be involved with fibrin formation and adhesions. The cystic duct is partially obstructed.

In the suppurative form there is marked congestion, desquamation, with a fibrinopurulent exudate and more or less ulceration. The cyst wall is dark red, green or blackish. The ulcerations may lead to perforation, local abscess or general peritonitis. Cystic duct is occluded. Dense adhesions may form.

If the process becomes chronic the gall-bladder may become greatly dilated with a thinning of the walls. In other cases it may become very small, sclerotic, and at times obliterated.