DYSENTERY. A disease which in man is characterized by the passage of blood and mucus, the bloody flux of former times. It results from the superficial and deep ulcerative action of certain protozoal and bacterial micro-organisms, primarily upon the large bowel and particularly its lower part. As dysentery may be due to diverse micro-organisms, the causal one or its family or generic name is employed to specify the type of infection, thus— amoebic, bacillary, spirochaetic, ciliar and helminthic dysentery, the first two being the most prevalent and of world-wide incidence.
The term has been given to passage of blood and mucus arising from ulceration of the lower bowel in diseases in which the activity of the causal micro-organism is not specifically selective for the lower bowel, but may occur in other parts, as in tubercle, syphilis, typhoid or paratyphoid. Again, passage of blood and mucus may be associated with a pathological state of the kidney, heart or liver or with carcinoma of the bowel, the impaction of a foreign body or mechanical irritation.
The term clinical dysentery is applied to a mild form of dysentery of short duration, seen especially in natives in the tropics, the aetiology of which is not yet known. In all forms of dysentery frequently there is abdominal pain and tenesmus, but one or both may be absent, for they depend on the site or extent of the ulceration.
The casual micro-organisms have been grouped. Protozoa and bacteria found in the intestine of man have been classified into pathogenic and non-pathogenic, and the varieties of form certain protozoal organisms undergo in their life histories in the intestines, or when, as some helminths do, they pass through a phase of existence in an invertebrate host, have been studied and made known.
The findings of Walker and Sellards in Manila from experi ments on condemned prisoners show that of the five amoebae found in man only one, Entamoeba histolytica, is pathogenic to him. Later Darling, James and others at Panama, differentiated it from the non-pathogenic E-coli. Recently Cutler, Boeek and Dr. Bohlar have cultivated E. histolytica in artificial media. In the Philippine Islands Vedder studied the specific action on amoebae of emetine, an alkaloid from ipecacuanha, and its application with beneficial results to man was first made by Sir Leonard Rogers in India. A new species of bacillus dysenteriae, B. dys. Schmitz, was first found in Rumania in I 9I 6.
Mechanical aids have been improved to obtain more precise clinical knowledge. The sig moidoscope, by which one can see aocm. up the bowel, is now em ployed to look for any ulceration and its character in this region and, if present, specimens for laboratory examination can be taken direct therefrom. Skiagrams taken after a barium mixture, given by mouth or injected per anum, indicate the movements and the nature of the bowel condition, and presence of any ulceration, filling defects, strictures or diverticula in its wall in subacute or chronic cases (see X-RAY) .
England and France the existence of bacteriophage has been determined. Regarding dysentery d'Herelle found that if a few drops of the filtrate from a broth culture of the faeces of a con valescent case of B. dys. Shiga be placed in a broth culture of this bacillus, the micro-organisms are dissolved (see BACTERIA
