554 THE DIGESTIVE SYSTEM. 



Anthrax Infection of the Intestine (Mycosis Intestinalis). The anthrax 

 bacillus may find lodgment in the intestinal mucous membrane either by 

 the ingestion of food containing the germ or by metastasis through the 

 blood from some other seat of infection, especially the skin. 



The intestinal lesions are most apt to occur in the small intestines and 

 in the upper part of the colon. The mucous membrane is studded with 

 larger and smaller brown or black frequently elevated patches, or areas 

 of local congestion, or haemorrhage, or necrosis. The mucous membrane 

 near the inflammatory and necrotic foci may be cedematous. Hyperplasia 

 of the spleen and lymph-nodes is apt to accompany the intestinal anthrax. 

 The anthrax bacillus may be found about the seat of local lesion in the 

 intestine, in the associated lymph-nodes, and when secondary to local 

 infection elsewhere it may be found in the primary lesion and in the 

 blood. 



It is believed that other forms of bacteria may cause intestinal lesions, 

 somewhat similar to those of anthrax, but the researches in this direc- 

 tion are not yet. sufficiently numerous to permit of very definite state- 

 ments. l 



INFLAMMATION OF THE LARGE INTESTINE. (Colitis.) 



The mucous membrane of the large intestine is frequently the seat of 

 acute and chronic inflammatory and necrotic processes known clinically 

 as dysentery.* The rectum is most often involved, but sometimes the up- 

 per part of the colon and sometimes the whole colon is affected. 



Acute Catarrhal Colitis. This process is frequently limited to the 

 lower end of the colon and presents several types. There may be an in- 

 creased production of mucus, which coats the surface of the mucous 

 membrane and is mixed with exfoliated and fatty or disintegrated epi- 

 thelium and red blood cells. The surface epithelium may be degenerated 

 and exfoliate, many "beaker cells" being present, indicating the source 

 of over-production of mucus (Fig. 330A). The mucous membrane may be 

 congested and infiltrated with serum and leucocytes. Again, with con- 

 ditions similar to those just described, there may be a purulent exudate 

 in the mucous membrane. There is a form of catarrhal colitis in which 

 there is a more or less extensive formation of new connective tissue be- 

 tween the glands and in the submucosa. Finally, there may be small or 

 extensive ulceration in the involved areas of the mucosa. 



Acute Infectious Colitis (Tropical Dysentery) is of especially frequent 

 occurrence in warm countries and is often epidemic. In one group of 

 cases (a) the disease is probably incited by protozoa amoebae coli ; while 

 in the other (6), bacteria, some apparently related to the typhoid-colon 

 bacillus group, and possibly others, are believed to be the excitants. 



1 For references to intestinal bacteria see footnote, p. 560. 



2 The classification of these lesions is with our present knowledge unsatisfactory, 

 and is largely based upon morphology. In some phases of so-called dysentery infec- 

 tious colitis however, the nature of the excitant is taken into the account. Consult 

 for a special study of forms of colitis seen in New York Delajield, Am. Jour. Med. Sci- 

 ences, vol. cxiv., p. 401, 1897. 



