566 AFFECTIONS OF THE INTESTINAL CANAL. 



whether cases of catarrh caused by coldness of the feet and of the 

 lower part of the body, which depends on the continued action of 

 cold, and the chronic cases induced by damp, cold climates, belong ir 

 this class. 



4. The severe intestinal catarrh frequently occurring in peritonitis, 

 particularly puerperal peritonitis, must also be considered as due to 

 excessive active hyperaemia. In these cases the intense inflammation 

 leads to oedema of the subserous tissue, of the muscular coat, and of 

 the intestinal mucous membrane. We see similar oedema occur in the 

 vicinity of all inflammatory disturbances of circulation, and we have 

 repeatedly described it as collateral oedema, or oedema from collateral 

 fluxion. It readily explains the watery passages, which often accom- 

 pany peritonitis, in spite of the paralysis of the muscular coat of the 

 intestines. 



5. Fluxion to the intestinal capillaries with consecutive serous 

 transudation appears also to be the cause of diarrhoea induced by men- 

 tal excitement. In these cases we must suppose that the afferent ves- 

 sels are dilated by nervous influence, and this hypothesis has at least 

 received some support, since Budge showed that there is constant 

 diarrhoea after extirpation of the coeliac ganglion in rabbits. 



6. In most cases hyperaemia and catarrh of the intestinal mucous 

 membrane are the results of local irritation. Most purgatives act in 

 this way, for very few of them purge, by acting as concentrated solu- 

 tions of salt, i. e., by endosmotically inducing a copious flow of liquid 

 from the intestinal vessels into the intestines, without exciting hyper- 

 aemia. Catarrh of the intestines is caused much less frequently than 

 was formerly supposed by large quantities of bile, and not very often 

 by the presence of parasites. In this class belong the cases of intesti- 

 nal catarrh occurring after the use of certain non-medicinal substances, 

 such as some kinds of vegetables, but particularly those cases due 

 to the passage of undigested and decomposing substances from the 

 stomach into the intestines (see etiology of gastric catarrh). It is 

 very frequently caused by the retention of fecal masses; if these 

 remain for a length of time at any part of the intestines, they decom- 

 pose, and form products which have a very injurious and irritant influ- 

 ence on the intestinal mucous membrane. To Virchow is due the 

 credit of calling attention to the frequent occurrence of local peritonitis 

 and the change of position, constriction, and twisting of the intestines 

 dependent on it. Indeed, these are in many cases the causes of habit- 

 ual constipation ; and some chronic ailments, which in general terms 

 are called " chronic abdominal difficulty," depend solely on distortion 

 and constriction of the intestinal canal, on the development of gases 

 from the decomposed faeces, or on consecutive intestinal catarrh. 



