In cases of the kind here described, it is not at all unlikely that the enlargement of the liver in the earlier, as well as its atrophy in the later stages of obstruction, may be mistaken for the cause of the jaundice, instead of the result of the arrest of the flow of bile, and thereby lead to a grave error in treatment. The history of the case, together with a knowledge of the above facts, will, however, tend to facilitate the diagnosis. Thus, it must be ascertained:—
Firstly,—If the jaundice preceded the alteration in size of the organ.
Secondly,—If there is an absence of any history of hepatitis; and,
Thirdly,—If there is no evidence of any pulmonary or cardiac mischief likely to lead to passive congestion of the hepatic tissue.
Even with a knowledge of all these facts, however, it often baffles the skill, and acumen of the ablest physicians to discover the cause of jaundice. Every now and then cases are met with, where the patient tells us that the jaundice has gradually come on without any assignable cause, and where, after the most careful examination of his history, as well as of his physical condition, we fail to detect a clue to the diagnosis. Cases of this kind are far from uncommon, and this is the more to be regretted, seeing that unless we have a clear appreciation of the cause, it is not only difficult, but even dangerous to treat the symptom. The injudicious administration of a remedy here, may hasten the termination we most desire to retard. The truth of this remark will, however, be better appreciated when I come to consider the rationale of the treatment of jaundice. Meanwhile, it may be advisable to point out a method capable of yielding most important information, when all the ordinary means of diagnosis fail. I allude to the chemistry of the excretions. Although the pathological chemistry of the excretions is as yet in its infancy, it has already given the scientific physician a key to the detection of several diseases, and I trust to be able to show, that even in the obscure cases of jaundice above alluded to, it not only gives us a clue to their cause, but presents us with a guide to their treatment.
In jaundice arising from obstruction, the pipe-clay stools are, as in the case of jaundice from suppression, entirely due to the absence of bile from the intestinal canal. The yellowness of the skin is in like manner caused by the accumulation of the bile pigment in the blood, from whence it exudes, and stains the tissues; and, lastly, the saffron-coloured urine results in a similar way from the elimination of the pigment from the blood by the kidneys. Instead, however, of these three conditions arising, as in the case of jaundice from suppression, from the arrest of the biliary functions allowing certain of the constituents of the bile to accumulate in the circulation, they are, in the first place, the result of the re-absorption of the secreted bile from the distended ducts, and gall-bladder. So that while in jaundice from suppression, only those biliary products which exist pre-formed in the blood accumulate in the circulation, in cases of jaundice from obstruction, the biliary products which are manufactured in the liver, equally with those which are pre-formed in the blood, find their way back into the circulation, to be from thence eliminated with the excretions. If then, we could ascertain the presence or absence of these products in the excretions, we should be enabled to distinguish between jaundice resulting from suppression, and jaundice arising from obstruction. Let us now see what the chemistry of the excretions teaches us; and to begin, we shall take the intestinal excretion.
ANALYSIS OF THE INTESTINAL EXCRETION AS AN AID TO THE DIAGNOSIS OF OBSCURE CASES OF JAUNDICE.
The intestinal excretion, in the natural state, consists, firstly,—of those portions of our food which have resisted the action of the digestive juices; secondly,—of the excess of the modified food remaining unabsorbed; and, thirdly,—of the excess, as well as of the effete portions of the digestive secretions themselves. Consequently, if from any cause the digestive secretions do not act properly, the evacuation immediately becomes abnormal, and we can discover by analysis which of the secretions is at fault. Thus, for example, we know that the saliva acts upon the starchy matters of our food, the gastric juice on the albuminous, the pancreatic on the fatty, and that the biliary secretion so modifies the chyme as to allow of its rapid absorption by the lacteal, and portal vessels. If then, from any cause the elaboration, or excretion of any of these digestive juices be interfered with, more of the particular kind or kinds of food on which it acts, passes unchanged through the intestines. Thus, if the salivary secretion be affected, an unusual amount of unmodified starch is found in the stool. If the gastric juice is defective, more albumen than is normal passes away unchanged, and so on with the others.
It is clear then, that an examination of the stools must afford us important information regarding the presence, or absence of the normal secretions. A simple inspection of the stool will sometimes at once tell us whether or not bile is present. If it be present, the stool varies from a pale yellow, to a dark olive-green hue, according to the kind, and quantity of biliary colouring matter present, and the nature of the food. It must not be forgotten however, that unless care be taken, the colour deducible from highly-coloured food may be mistaken for an excess of bile. This remark is still more applicable to medicines, for mercury, bismuth, iron, and some other mineral remedies, give rise to dark evacuations so closely resembling bilious stools in appearance, that the only way to distinguish them, is by chemical analysis; when, the presence of the mineral, together with the absence of the bile pigment, and the biliary acids (which are always to be found in normal evacuations), will at once reveal the true nature of the case. I have seen a mistake of this kind happen, and that too, where a patient labouring under jaundice from obstruction, was thought to be passing the usual amount of bile in his stools, when in reality not a particle of bile pigment was present. The colour was in this case entirely due to the food, and ferruginous remedies. Blood from the stomach or bowels, is also apt to be mistaken for biliary matter, more especially when acted on by the gastric juice, which has the property of turning red blood brown. With these exceptions, the absence of bile from the stool, is usually very easily ascertained. For if the patient be taking no highly-coloured food, or any of the medicines above indicated, the stools are of a dirty pipe-clay colour. This is not due to the presence of any new or foreign matter, but solely to the absence of bile pigment. In these cases the evacuations, besides being white, are usually of a most offensive odour, for, among other things, bile checks intestinal putrefaction, and the development of offensive gases.
In addition to the colour, and odour of the fæces, in cases of jaundice, another important indication is to be found in the presence of fat. The presence of fat in the stools was at one time looked upon as evidence of pancreatic, at another time of hepatic disease; now, however, experimental physiology has taught us, that it in some measure depends upon both. For while, on the one hand, the pancreatic secretion emulsions the fatty part of our diet, and thereby renders it capable of absorption, recent researches, as has been already pointed out, have established the fact that the biliary secretion also plays an important part in the absorption of the oleaginous constituents of our food. Bidder and Schmidt, as was before said, have shown that a dog, after ligature of the gall-duct, absorbs less than half the average normal quantity of fat; and by experiment it has been found that this arises from the circumstance that bile emulsions only the acid fats, while pancreatic juice transforms the neutral as well as the acid oleaginous matters. The presence of fat in the stools may be due, therefore, partly to hepatic, partly to pancreatic derangement; and I shall immediately point out how we can turn this fact to account in diagnosis, and discover in cases of jaundice from obstruction, whether the seat of the obstruction be at the outlet or in the course of the duct.