Renal calculi were found so frequently in gall-stone cases that a definite rela tionship was thought to exist between the two conditions. On the other hand, Naunyn has rarely found the two dis eases combined.
A villous condition of the inner sur face of the gall-bladder has been given as a predisposing cause.
It is generally thought that cancer, with which cholelithiasis is so frequently combined, is caused by irritation of the calculi. It would, however, seem prob able that roughening of the surface, catarrhal cholecystitis and cholangitis, which frequently occur in the early stage of the disease, as well as the par tial obstruction which must often take place, would all predispose to the forma tion of calculi.
Cralbstones probably form aronnd a nucleus of precipitated bile-salt result ing entirely from local changes. The calcium salts and bile-pigments are read ily precipitated whenever there is an in crease in the albuminous constituents of the bile, and this increase is par ticularly marked when inflammatory changes occur in the bile-passages. Cholesterin is especially abundant when any degenerative process is going on, as there would be in disease of the gall duets. and this cholesterin is deposited around the nucleus. The most frequent causes of such catarrh is infection by micro-organisms, the bacilli coli coin immis and the typhoid bacilli being par ticularly apt to originate such disturb ances. The latter may have laid dor mant for many years before acting as excitin!! ap'ent. AV. H. Thomson (New York Med. Jour.. March 1, 1p02.).
The relation which insanity bears to cholelithiasis has long excited interest.
The more frequent occurrence of gall stones in insane people is probably due, in large measure, to their sedentary habits. The opinion has also been given that great nerve-waste may produce an excess of cholesterin.
Sedentary habits are, no doubt, a very- important predisposing cause. The flow of bile, which under ordinary cir cumstances takes place under very low pressure, is much influenced by the movements of the body and especially by the movements of the diaphragm.
When, therefore, the body is in com plete repose, stag.nation of the bile will more readily take place, and the soft cholesterin masses which form the nu clei of gall-stones do not pass out of the gall-bladder. but are coated by,- a more dense layer of cholesterin or bilirubin- 1 calcium, and thus become too large to pass through the cystic duct. Condi tions which interfere with the movement of the diaphragm—such as empyema and pregnancy—have the same effect.
Authoritative views with regard to the influence of diet have been divided, and , of late years its importance has been much doubted. Experience has shown that, in cases of biliary fistula, fari naceous and saccharin food will produce a dense, thick bile, whereas an albumi noid diet will cause the biliary secretion to be more liquid. A dense, thick bile will act in the same way as if it were stagnant: in favoring the formation of calculi. Frerichs thought that a small number of meals, with too long an in terval between them, prevented the proper emptying of the gall-bladder, and thus predisposed to the formation of calculi.
It was at one time thought that too much lime in drinking-water predis posed to cholelithiasis; this has, how ever, not been substantiated. Climate does not seem to have any- great influ ence.
A summary of our present knowledge regarding the etiology of cholelithiasis shows that gall-stones may originate either in the gall-bladder or in the intra hepatic duets. In a large majority of cases they oecnr in the former situation and are the result of catarrhal and other inflammations. The formation of bili rubin calculi in the intrahepatic ducts is caused by catarrhal inflammation, probably the result of the excretion of some irritating substance. It is pos sible, also, that a microbic invasion may take place either through the common bile-duct or from the blood-vessels; but the latter is not likely.Ernbin-cal cium calculi may form in the intrahe patic ducts and pass through into the gall-bladder, becoming the nuclei of larger stones.