ACUTE COLITIS. 381 



exceedingly frequent affection, the most prominent clinical 

 feature of which is diarrhoea. The watery consistency of the 

 stools is due, not so much to the inflammatory serous exuda- 

 tion, as to the increased peristalsis, which permits of less time 

 for the abstraction of the fluid constituents of the intestinal 

 contents. 



The inflammatory process is caused by improper food, espe- 

 cially that in which poisonous alkaloids have been formed 

 during putrefactive changes ; also by inorganic poisons, like 

 arsenic and antimony ; and it may occur secondarily in the 

 course of various infectious diseases. 



Lesions : The mucous membrane is red and sw r ollen, often 

 covered with mucus; and here and there maybe small hemor- 

 rhagic spots. The solitary and agminated lymphatic follicles 

 are swollen, and appear as small, dull gray prominences upon 

 the mucous surface ; small pitted, so-called follicular ulcers 

 result if these lymphatic glands undergo necrosis. In severe 

 cases the raesenteric glands are enlarged. When the inflam- 

 matory process becomes chronic, the rnuscularis is in- 

 volved, as in gastritis, and often much hypertrophied. Some- 

 times polypoid elevations are produced by proliferation of 

 glandular elements. In the later stages there may be atrophy 

 of the mucous membrane alone, or involving, in addition, the 

 muscularis. 



A duodenitis may be associated with an inflammation of the 

 stomach. It is exceedingly liable to produce an obstruction 

 of the common bile-duct by inflammatory swelling of the 

 mucosa and accumulation of mucus, thus giving rise to reten- 

 tion of bile and an obstructive or catarrhal jaundice. 



Acute colitis is, in the great majority of instances, associated 

 with the condition recognized clinically as dysentery. Sporadic 

 cases result from ingestion of tainted food, from mercury and 

 other poisons. The infectious nature of the epidemic form 

 naturally suggests itself. The amoeba coli, a unicellular amoe- 

 boid body, measuring twenty to fifty microns in diameter, is 

 found not only in the stools, but also in the intestinal wall 

 adjacent to the dysenteric ulcers, and in the pus in hepatic 

 abscesses secondary to dysentery. Typical dysentery has 



