Foreign bodies, such as fecal concretions, gall-stones, stones of fruit, bones, coins, and pins, by remaining in contact with the mucous membrane for a length of time, determine inflammation and ulceration.6
6 Lothrop, "Case of a Child in whom seventeen plum-stones, three cherry-stones, and seven small bones were impacted In the cæcum and ileum for a year. Inflammation, ulceration, and perforation of the bowel resulted" (Buffalo Med. and Surg. Journ., March, 1882, p. 346).
Neglect in the treatment of acute catarrh, the prolongation of an acute attack, from its intensity and the incurability of the lesions, establish chronic disease.
All chronic lesions of the bowel are complicated with chronic catarrh, as chronic tubercular ulcer, neoplasms in the wall, pressure of a tumor from without, etc.
PATHOLOGICAL ANATOMY.—The alterations in the intestines in chronic catarrh involve the walls to a much greater extent than in the acute form.
The intestinal tube is dilated, contracted, or irregularly dilated and contracted. When the calibre is increased the walls are thinned. Hypertrophy and hardening of the tunics, chiefly of the muscular and submucous tissue, are accompanied by a narrowing of the canal, and this change, most common in the rectum and sigmoid flexure, sometimes involves a very considerable extent of the colon. Lebert records the case of a woman who had diarrhoea for six weeks; constipation and vomiting with abdominal tenderness ensued. There was hypertrophy of all the coats of the stomach and of the ascending colon and rectum. The rectum was so narrowed by the thickening of its wall that a female catheter could not be passed through it.7 In chronic catarrh the mucous membrane of the colon and of the lower part of the ileum is the seat of the most characteristic lesions. The colon was alone the seat of disease in 9 out of 99 cases analyzed by Woodward; in the remaining 90 the two were involved together. In these the lesions in the colon (especially in the rectum and sigmoid flexure) were always more advanced and more serious than in the small intestine.
7 Lebert, Path. Anat., t. ii. pp. 247, 248; another case, Laboulbène, Anat. path., Paris, 1879, p. 194.
Gastric catarrh may by extension become duodenal catarrh, and from the duodenum the disease may extend into the common bile-duct and its branches. The duodenitis and catarrh of the ducts may persist, and become chronic after the stomach lesion is gone.
The mucous lining of the intestine is changed in color, form, thickness, consistence, and in the appearance of its glandular structures. The shades of color in chronic inflammation are dark red, livid, brown, drab, or slate-color, light blue, and greenish. The coloration is not uniform. Dark-red and gray spots are seen on a pale and uniform red ground; grayish streaks and patches are mingled with red or whitish areas, giving rise to a mottled or marbled appearance.8 In some cases red predominates, in others the slate-color.9 Dark-brown, almost black, patches are also seen. These different tints depend upon the intensity and character of the inflammation and the stage which it has reached. Diffused bright-red discolorations belong to acute inflammation, and are rarely seen in the chronic form. Acute hyperæmic patches appearing in the midst of a slate-colored membrane indicate intercurrent acute attacks. Dark-red streaks or spots are caused by extravasations. Brown and slate-colored areas represent the changes in old extravasations or pigment-deposits where inflammation or ulceration has existed. Where the inflammation is progressing toward the destruction of tissue the membrane is dark-purplish or black in color, mottled with patches of dull reddish hue and minute spots of bright red. Black dots are seen in the small and large intestine isolated or in close proximity. They are due to minute specks of black pigment deposited in the apices of the villi, in the centres of solitary glands, in rings around them, or in the glands of a Peyer's patch. The juxtaposition of pinhead black points gives rise to the shaven-beard appearance10 of the mucous membrane. Dark streaks or wavy lines of pigment are also seen.11
8 For illustration of color of mucous membrane in chronic inflammation see the following illustrations in color: Med. and Surg. Hist. of the War, Part 2, Medical Volume—plates facing pp. 308, 518, and 520; also, Illustrations of Morbid Anatomy, J. Hope, London, 1834, figs. 128, 129.