In the large intestine the same lesions are found, but in a more advanced stage, especially in the cæcum and descending colon. Enlarged solitary glands of the size of a pinhead or small bird-shot are scattered along the canal.
Follicular ulcers20 are found in the large intestine, occupying the summit of the enlarged follicles and involving a large extent of mucous surface. Pigment-deposits are seen which give rise to the appearances described as occurring in chronic intestinal catarrh.
20 For description of the mode of formation and growth of follicular ulcers see article on [CHRONIC INTESTINAL CATARRH].
(e) The mucous surface is covered, especially in the areas of redness, with an adhesive, opaque mucus of neutral or alkaline reaction and of yellow, red, or brown hue, depending upon the relative amount of bile or blood. It is composed of mucus-corpuscles, epithelium-cells of cylindrical and prismatic form, pus-cells, and sometimes blood-corpuscles. Vibrios and bacteria also are seen.
The chief distinction between the lesions of acute intestinal catarrh and typhoid fever are these: In typhoid fever the number of Peyer's patches involved is larger; there will be a chain of enlarged glands from the ileo-cæcal valve throughout the ileum, those nearest the ileum being the most altered. Near the valve there is usually some ulceration, so that the gland acquires a ragged appearance. In catarrh of the bowel there is a more irregular distribution of enlarged glands; they project less above the surface, and if ulcerated have one or two spots of erosion. In typhoid fever the Peyer's patch has the most prominence. In catarrh of the bowel the solitary glands are the most enlarged. In catarrh the large intestine may be the seat of the most advanced lesion; in typhoid fever, except with rare exceptions, the lesions in the ileum are most advanced.
(f) The mesenteric glands are enlarged, but not so uniformly so or to the same extent as in typhoid fever. The stomach is sometimes found inflamed, the mucous membrane being reddened, thickened, or softened. The liver, spleen, and kidneys are normal or present accidental conditions of disease. In the respiratory organs pulmonary congestion, pleurisy, and pneumonia are found. The heart contains clots which are fibrinous or soft and red; they are found on both sides, but when one cavity alone is filled the right is the common seat. The brain is usually normal; fluid may be in the subarachnoid space, and thrombi in the cerebral sinuses.
PATHOLOGICAL HISTOLOGY.—In the genesis of catarrh of the intestinal mucous membrane the first effect of the exciting cause is an over-distension of the capillaries and small vessels; this congestion is most marked in the meshwork of vessels around the closed follicles. A transudation of serum takes place into the mucous layer, and in more marked congestion into the submucous layer also; these tissues become more or less oedematous and swollen. Transudation of serum into the intestinal tube follows. From over-stretching the walls of minute vessels may rupture and small extravasations take place, staining the tissue red. These subsequently become black pigment-spots. Post-mortem extravasations are due to decomposition of the wall of the vessel. Rupture of vessels on the surface leads to escape of blood into the bowel, which is mixed with the transuded serum. The proper secretion, intestinal juice, is diminished as a result of these changes, but an excess of the mucus with which the mucous membrane is always coated immediately follows. The origin of the mucus is not to be sought for in the activity of the glands alone, but in the transformation of the protoplasm of the epithelial cells.21 The varying proportions of serum, mucus, and blood cause the stools to be serous, mucous, slimy, or bloody, hence the terms serous, mucous, and bloody diarrhoea.
21 Rindfleisch, Path. Histology, Sydenham ed., vol. i. p. 412.
Hypernutrition, swift life of the mucous membrane, the result of continued excess of blood, entails the increase of the cell-elements. Lymphoid cells accumulate in the submucous layer, especially where these cells are normally most numerous. There is a saturation of the membrane with an excess of plasma. Cells also appear in increasing numbers in the interfibrillary spaces of the mucous membrane, which increase its bulk, and the follicles of Lieberkühn appear as if pushed apart. Lymph-corpuscles accumulate in the meshes of the closed follicles, which are distended and project above the surface as described. Multiplication of the cells within the follicle (follicular suppuration) causes over-stretching and the wall bursts, forming the first stage of the follicular ulcer. The appearance upon the epithelial surface of an increased number of loosened cells, which are sometimes epithelial in character and at other times resembling pus-cells (epithelial and purulent catarrh), is believed to be due to a rapid manufacture and exfoliation of epithelial elements, and to constitute one of the essential features of catarrh. Desquamation of the epithelium in catarrh of the bowel, even in that of Asiatic cholera, has been called in question by Woodward, who thinks that the stripping off of epithelium is cadaveric.
SYMPTOMS.—Owing to the difference in the intensity and extent of the catarrhal process there is every possible variation in the symptoms of intestinal inflammation. No one symptomatic picture will properly represent all cases, and with a view to greater convenience and exactitude of illustration a division may be made into mild and severer forms.