The presence of tubercle in the tissue of the intestinal mucous membrane, and by extension, in the deeper-seated coats, constitutes a most important disease - tuberculosis of the intestine in the wide, tuberculosis of the intestinal mucous membrane in the narrower sense. It may proceed to ulcerative destruction, and this establishes genuine intestinal phthisis.

Amongst ourselves this affection rarely occurs in the idiopathic form, except during the first years of life. It is commonly the consequence of pulmonary tuberculosis, and in the majority of cases, takes place after the latter has attained the suppurative stage (pulmonary phthisis), and the general tubercular cachexia has become fully developed.

The course it runs is frequently chronic, but much oftener acute: the latter is more particularly the case when it follows the tumultuous fusion of numerous pulmonary tubercles. The tubercular deposit offers corresponding varieties in reference to its original form, its seat, and its metamorphosis.

In the chronic affection we find the mucous membrane, and the adjacent layer of submucous cellular tissue, to be the original seat of the tubercular deposit; there is no perceptible inflammatory action, and the disease appears in the shape of the gray, transparent, tubercular granulation, which softens at its centre, and is gradually converted from within outwards, into the yellow cheesy tubercle. It seems blended with the mucous membrane, and projects into the intestinal cavity in the shape of a sessile, hard nodule.

When the local appearance of tubercle takes place in the acute form, there is considerable inflammatory action. The deposit is effected similarly to that occurring in the pulmonary cells; in the first instance it is deposited in the cavity of Peyer's glands, then into the solitary follicles, and lastly, in every other part of the intestinal mucous tissue; it appears in large masses, and in the shape of yellow, cheesy matter, which speedily undergoes a purulent transformation. The surrounding tissue is found extensively congested, reddened and turgid; and when the deposit is excessive, the mucous membrane of an entire coil may be in a state of congestion and irritation. In this case tubercular tumors, either scattered over the surface of the intestine or more or less accumulated, are found occupying Peyer's patches, offering considerable projections and distinguishable through the mucous membrane by their yellow tinge.

Tubercular deposit in the intestinal mucous membrane, being the result of a fully-developed tubercular cachexia, commonly advances rapidly to softening, and this process is effected with peculiar violence in the second variety. The investing mucous membrane gives way at its most elevated point, and as the orifice enlarges, the suppurating tubercular matter escapes.

A cup-shaped ulcer, of the size of a millet seed or a pea (the primary tubercular ulcer) results; its margin is ,firmly attached, rounded and indurated, and of a pale or red color in proportion to the reaction that occurs in the surrounding tissue; its base is either formed by the condensed submucous cellular layer, or by the granulated texture of the parietes of the dilated follicle. It is only in very rare cases that the tubercle fuses under the mucous membrane without giving rise to perforation; it then forms at the expense of an inclosed abscess, which enlarges the submucous cellular tissue (vomica submucosa).

The increase of the ulcer takes place with more or less rapidity, it loses its original form, but only to exchange it for a more characteristic secondary one.

The increase is effected by fusion of the tubercular infiltration of the margin of the ulcer, and by concurrent suppuration of the tissue. In the first instance, the small adjoining ulcers coalesce into one of larger size; the common base presents sinuous projections of the common margin of mucous tissue, ridges of mucous membrane may be seen traversing it in various directions, or even solitary insular remnants of this tissue are found upon it.

If this process has occurred, as it does in acute intestinal tuberculosis, in one of Peyer's patches, the ulcer may, on account of the elliptic form prescribed by the shape of the glandular apparatus, be mistaken for a typhous ulcer, but we shall immediately point out that the peculiar relations of the margin and the base afford a satisfactory clue to the diagnosis.

The ulcer, which is formed by a coalition of other smaller ulcers, enlarges in the same manner as the original solitary ulcer, in the direction of the intestinal circumference, and at last presents a zone of varying width and uniformity. Its margin is sinuous or dentated, inverted and tumid, and is formed by mucous membrane of a light red color; from the latter being infiltrated with a transparent gelatinous substance, an analogy is offered with the gelatinous infiltration occurring in the vicinity of tubercular pulmonary abscesses. The base is formed by callous cellular tissue of a dirty white color, underneath which the remaining intestinal layers are found similarly condensed and tumefied.

Both in the marginal tissue and at the base we find a deposition of gray, or more commonly of soft, yellow, tubercular matter. The ulcer presents a very peculiar appearance, on account of the remnants of mucous membrane seen on its base. These adopt the characters of the margin, and become infiltrated with gelatinous matter, so as to form crispated, transparent, condylomatous excrescences of a light-red color.

In the same manner as the tubercular ulcer extends laterally, it may advance in the opposite direction, and thus giving rise to perforation, cause sudden death. Secondary deposition of tubercular matter may equally take place in the callous cellular tissue of the base, and as it fuses at this point, in the muscular and subserous layers also. The peritoneum may become perforated in consequence of tubercular suppuration being established in it, or in consequence of mortification induced by the approach of an abscess. It follows that the tubercular ulcer perforates the intestinal parietes without losing its original character, inasmuch as the progress of the tubercular affection is not arrested by an isolating tissue; in this it differs from the typhous ulcer, which does not perforate the intestine in its original form, but affects the parts beyond the submucous cellular tissue in its degenerated character.

At an earlier or later period we find moderate inflammation attacking points of the peritoneum which correspond in position to the intestinal ulcer; a fibrinous exudation results, which is entirely, or in part, converted into tubercle; in the latter case it is partly converted into cellular tissue. By the intervention of this new product an adhesion is often effected at the point of ulceration, between the intestine and a neighboring organ, e. g. the bladder, the omentum, and thus a more or less substantial impediment is offered to the free discharge of the intestinal contents into the peritoneal cavity on the occurrence of perforation.

The mesenteric glands, lying in the vicinity of the affected portion of the intestine, are variously enlarged: in the primary intestinal tuberculosis of children they frequently attain the size of a walnut or hen's egg; they appear tuberculated and pale, and present a deposition of grayish, medullary, and hard, or of yellow, grumous, and deliquescent, tubercular matter.

The small intestine is the common seat of intestinal tuberculosis, and in most cases the disease is limited to this part; still it often passes on to the colon and descends to the rectum, or it ascends into the jejunum, and in very rare cases mounts to the duodenum and the stomach. Sometimes it is much advanced in the colon and then appears to have been first developed at this point and subsequently to have extended to the small intestine.

"We may gather from the circumstances accompanying intestinal tuberculosis, that the further it has advanced the less a cure is to be hoped for. Still in the same manner as in the tubercular abscesses of the lungs, we sometimes obcerve a healing process established in a few among a large number of ulcers. It takes place in the following manner.

The first indispensable condition is the cessation of all secondary tubercular infiltration at the margin or base of the ulcer; the callous base is then condensed into a fibro-medullary cord, and the edges of the ulcer approach one another. This process sometimes advances so far, that the dentated edges almost touch, and between them a whitish, callous cord may be observed. Occasionally, the edges are soldered together over the callosity, yet so as to leave a fissure at one end of the ulcer. In very rare cases an entire consolidation is effected.

In consequence of the contraction of the ulcer, a cicatrix forms on the surface of the intestine, which presents a more or less elevated tumid ridge on the internal surface of the intestine. If the ulcer was of considerable size, or if it encircled the entire intestine, a callous annular ridge remains, which diminishes the calibre of the intestine, and when viewed from without, occasionally gives rise to an appearance of invagination.

Thus the cure of a tubercular intestinal ulcer is always accompanied by a diminution of the intestinal calibre.