DYSENTERY must not be confounded with the acute catarrh of the sigmoid flexure and rectum which is so common in children, and also gives rise to severe tenesmus and pain. The affection, when it runs its ordinary course, is not, strictly speaking, a diarrhoea. Faecal matter is passed rarely, and then only as small hard scybalous masses enveloped in mucus —stools which bear no resemblance to the slimy feculent motions which constitute a familiar symptom of inflammatory intestinal catarrh. True dysentery is a specific disease which often occurs in epidemics, although sporadic cases are occasionally met with. It is rarely seen in England, except in the chronic form—the result of a previous acute attack in chil dren who had been resident abroad.
Causation.—Dysentery is common in tropical climates, especially in places which are badly drained, and therefore damp, and where the air is loaded with the emanations from decaying vegetable matter. On account of being thus endemic in ague-breeding districts, the disease has been thought to have some affinity with intermittent fever ; but it been shown that dysentery is not necessarily generated in malarious spots, and that it may occur in places where ague is unknown. Foul air, impure water, bad drainage generally, and rapid alternations from extreme heat to coolness of the atmosphere are the causes to which the disease is especially attributed. In a case which was under my care in the East London Children's Hospital—a little boy of five years old, in whom, after death, the mucous membrane of the whole large bowel was found to be converted into a purplish-black slough—the illness had begun suddenly during very hot weather, and was attributed to foul emanations arising from the of the dust-bins of the street in which he was living. It is well known that amongst the poor these receptacles are charged with refuse of every kind, and are often most offensive from the presence of de caying organic matter. Faulty nutrition and chronic digestive derange ments appear to be predisposing causes which may incline the child to be more readily affected by the injurious influences him. The disease is therefore said to be more common in hand-fed babies than in infants at the breast. The affection, when it occurs in epidemics, has a
tendency to propagate itself. The emanations given out by the dejections of a dysenteric patient are said to possess peculiarly noxious properties, so that any one incautiously inhaling the effluvium is likely to take the disease.
Morbid Anatomy.—In the earliest stage of dysentery the mucous mem brane of the colon and rectum is congested, and is swollen from inflam matory infiltration into its substance and the underlying areolar tissue. The colour of the membrane becomes rosy red, or may pass through the various shades of purple to slate gray of a very deep tint. At the same time the solitary glands project from the surface, and are enlarged to the size of a millet seed or a small shot. The inflammation sometimes occurs in patches, which are separated by more or less healthy-looking membrane, and these run together so as to cover a considerable extent of surface. A false membrane may be found adhering to the inflamed area. This can be separated as a thin opaque film which dips down into the fol licles of Lieberktihn. It consists of an inflammatory,hypeiTlasia of the follicular epithelium.
If the disease pass beyond this stage, superficial ulcerations are seen. Sloughs form upon the surface, and separate, exposing ragged, irregular ulcers with swollen, abrupt edges. Dr. Parkes was of opinion that the ulcers began in the distended follicles. Dr. Maclean believes that they are produced by sub-mucous purulent effusion which detaches the mucous membrane. This becomes gangrenous and is thrown off. The sloughs vary in size. If the process is rapid, large sloughs may be detached, and sometimes casts of the intestinal tube are eliminated unbroken. Their tint is yellow or ash-coloured, or even almost black. The ulcers are cir cular irregular in shape, and are large or small according to the extent of mucous membrane destroyed. The floor of the ulcer is usually formed of the sub-mucous tissue, but the lesion may extend to the muscular coat, or may even perforate the bowel as in typhoid fever.