§ 2. disease, which was at one time much more common in our own country than it now is, still continues to be one of the most serious affections of tropical climates. It presents to us the most severe form of inflammation of the mucous membrane, tending to very extensive ulceration.
In its pathological relations it is probably allied to acute diarrhoea with great irritation: the instances are, perhaps, more numerous than we are aware of in which the local action predominates, and the fever is only symptomatic, though they be at present regarded as fever with bowel complication, except when symptoms arise which are more distinctly dysenteric. Such appear ances can only be seen when the large intestine is the principal site of the dis eased action, because, if it were confined to the upper part of the bowel, while the colon remained healthy, the secretions would be so changed in their pas sage that the peculiar characters could not be observed ; and, indeed, this is in part true of dysentery itself as affecting different portions of the colon. On the other hand, there are good reasons for regarding true dysentery as something quite distinct from affections of the small intestine in which febrile symptoms are present; and, perhaps, as we have ceased to regard the ulcera tion of the ileum as anything more than a symptom of common bowel-fever, we ought to regard the ulceration of the colon only as a symptom of another " fever;" at all events, we find that, as in the one the ulceration seldom affects the colon, and then only in its upper end, so in the other, the ulceration seldom extends any distance from the colon into the small intestine.
The chief symptom relied on in dysentery is the passing of bloody mucus with hardened scybalous masses of feculent matter; but this is really the evidence of a mild attack, in which the lower part of the colon is alone involved. In the severer cases diarrhoea first 'comes on, emptying the whole of the large intestine ; and only subsequently do bloody and mucous discharges, with tenes mus, occur. Its commencement is generally sudden, with pain in the abdomen, in the hypogastrium, and perhaps especially on the left side : if the lower end of the colon only suffer, the feces from above are passed as scybala • glairy bloody mucus is discharged, which in a short time becomes purulent and offensive, and as ulceration proceeds a greater amount of hemorrhage generally continues : teneamus is always a distressing symptom, and is some times conjoined with irritation of the bladder and the urethra. When the pyrexia is not very evident, it is of importance to ascertain that the blood does not come from the rectum, where local disease may exist, either in the form of haemorrhoids, or as cancerous or fungoid growth.
Chronic dysentery might almost be classed under ulceration, for under no other circumstances does ulceration proceed so far; but we have reason to regard it as a specific disease, as it gene rally follows on an acute attack : the patient has probably been in a tropical climate, the bowels have since been always irregular, the motions unhealthy, commonly mingled with pus or muco purulent secretion, and often with blood. The disease, however,
remains quiescent until something arouses it to fresh activity ; some disorder of stomach, or exposure to cold or wet brings on a partially acute attack : or else, from the extensive disorganiza tion which has occurred, enormous accumulations arise in the colon, which it is unable to propel : these cannot be effectually got rid of by the aid of remedies ; low, wasting, suppurative fever supervenes, with gradual exhaustion, or the diseased structure is attacked by low inflammation, terminating in a condition allied to sphacelus.
§ 3. Ukeration.—Little can be said to elucidate this form of bowel ailment. We know it to exist in phthisis, and in continued fever : and in either case when there is irritability of the canal, with watery, unhealthy, and frequently fetid stools, and the tongue is glazed or aphthous, we have good grounds for concluding that ulceration is going on. We may, perhaps, also be justified in predicating it, when in other instances similar conditions persist, in spite of treatment, and we are unable to discover any other disorder of the abdominal viscera to account for their presence. It is not common as an idiopathic disease, and it may exist for long periods without giving rise to any distinct symptoms at all.
Hemorrhage is perhaps one of the most certain indications when it occurs spontaneously and in considerable quantity ; the appearance of the blood, in some measure, aids in determining from w'hat portion of the canal it comes, because its coloring matter is very readily acted on by the secretion of the bowels, and can only present a florid aspect when the point of its discharge is situated near the anus : the color is otherwise black, and hence the name of "mehena" has been given to this form of hemorrhage. Evacuations of similar character occur when the blood comes from the stomach, and the blackest and most pitchy evacuations are seen when this is their source. Hoemateme sis would of course determine that blood had been effused into the stomach itself, but, though a common consequence of its presence, it is by no means essential, and must not be made the basis of an absolute rule in diagnosis.
The presence of pus in the stools can only indicate ulceration low down in the canal: its quantity cannot be large unless the ulcerated surface be such as is seen in dysentery, and its admixture with feculent matter must necessa rily alter its characters and prevent its recognition if it pass through any great length of the intestine. A red and glazed tongue, with a tendency to the fbrmation of aphthous crusts, has been before alluded to as indicating a general state of the mucous membrane which is disposed to ulceration; it is seldom noticed, however, except in cases of phthisis or bowel-fever.