176 DISEASES OF THE INTESTINES 



change in the structure of the mucosa or occur during the 

 course of certain diseases attended by hemorrhagic diatheses. 

 Etiology.— The causes of intestinal hemorrhage are quite 

 numerous: (a) Mechanical agents, such as sharp foreign 

 bodies which penetrate the intestinal mucosa and injure the 

 bloodvessels, producing a more or less severe hemorrhage. 

 Parasites, by their irritating action on the mucous membrane, 

 or by burrowing into the mucosa, will produce the same 

 result. Injuries, such as being run over by vehicles, kicks, 

 blows, etc., over the region of the abdomen will often rupture 

 some of the vessels in the intestinal mucosa, resulting in 

 hemorrhage. Powderetl glass, when administered to destroy 

 animals, will produce severe hemorrhage by the fragments 

 of glass penetrating the mucosa and opening the vessels. 



(b) During the course of poisonings by chemicals or caustic 

 substances, severe hemorrhage often takes place due to the 

 corrosive action on the mucous membrane. Drugs, when 

 administered in large doses, may produce a congestion of the 

 bloodvessels of the mucosa, resulting occasionally in over- 

 distention and rupture. 



(c) Hemorrhage takes place sometimes from an engorge- 

 ment of the intestinal circulation from diseases of the heart 

 and liver, hemorrhagic infarction of the bowel from embolism 

 or thrombosis of the mesenteric vessels, intussusception or 

 strangulation of the bowel, or hernia. In these cases the 

 hemorrhage may result from an overdistention of the blood- 

 vessels. 



(d) During the course of some diseases severe hemorrhage 

 in the intestinal tract occurs, as in anemias, severe infections 

 (distemper) and certain degenerations. 



(e) Tumors (carcinomas) and ulcerations on the mucous 

 membranes may lead to severe hemorrhage by destruction 

 of some of the bloodvessel walls. Hemorrhoids, collections 

 of feces, etc., may produce hemorrhage in the large bowels. 



Symptoms. — Hemorrhage in the intestinal tract is often 

 difficult to recognize, unless the.quantity of blood is sufficient 

 to distend the bowels, or be ejected through the rectum. In 

 mild cases of hemorrhage only general weakness and paleness 



