Gall-stones, calculi of the gall-bladder, are solid masses resulting from the precipitation of various substances from the bile. They are most frequently found late in life and most commonly in women. It would seem that they form about a nucleus composed of desquamated epithelium, bacteria, the typhoid and colon especially, thickened mucus, or a foreign body from outside. Upon this body is deposited a layer of biliary salts; more layers are built up until a fairly large stone is found. This process is hastened if there is stasis, some decomposition of the bile, and a low-grade catarrhal inflammation. Instead of one large stone, several may form, or there may be thousands, like grains of sand.

The shape depends upon the number present. If single, it may be round or ovoid. Usually the sides are flattened by mutual pressure, giving an irregular crystal-like form. The color of the stones varies, according to their composition, from light yellow, through various shades of brown to black.

Fig. 161. - Types of Gall-stones. (From a photograph in the collection of Dr. Jepson, Sioux City, la).

a, Caused complete intestinal obstruction for eight days; b and c were removed from the gall-bladder and show points of attrition; d, solitary stone removed from gall-bladder; no point of attrition; e, gall-stone of irregular shape, due to compression or moulding; /, solitary stone from common duct.

They are generally formed in the gall-bladder, but may originate in the larger ducts.

The common variety is yellowish or brownish and is composed mainly of cholesterin and bilirubin in combination.

Other forms of calculi are made up of cholesterin, of bilirubin, and of calcium carbonate.

Although biliary calculi may exist for years without giving rise to any disturbances, they frequently cause more or less serious lesions. The gall-bladder generally shows some catarrhal inflammation, accompanied by some obstruction to the free flow of bile. The walls may exhibit slight or marked changes, they may be much thickened, ulcerated, or pouched. The mucosa must not be entirely destroyed or the choles-terin-producing function will be lost. The calculi may escape from the gall-bladder as a result of ulceration with perforation. Is fairly common in cholelithiasis and most frequently perforate externally.

The most severe symptoms result when one of the calculi escapes from the gall-bladder into the cystic and common bile-ducts. This gives rise to biliary colic, a very severe form of pain which is associated with symptoms of collapse. If the stone is small, it can pass on through the ducts into the intestine. It may, however, become lodged in the lower part of the common duct, usually just above the outlet into the duodenal papilla. Following the blocking of the common duct there is retention of bile, which if long-continued gives rise to marked jaundice and lesions within the liver. The flow of bile may be resumed by dislodgment of the stone or by the establishment of a passage around the foreign body.

An accompanying symptom of biliary colic is an intermittent fever in which the temperature may go up to 1040 or 1050 F. at the onset. It then subsides and reoccurs.

Tumors of the gall-bladder are quite uncommon. About the only form is a primary carcinoma arising from the mucous glands. This growth seems to be quite frequently associated with gall-stones, which may be causative or merely the results of the stagnation of the bile. The liver is soon secondarily involved by direct extension.