DIARRHCEA. 637 



II. DiARRHCEA. 

 A. ORDINARY DIARRHCEA, SPECIALLY OF THE ADULT. 



Definition. — An increase, as compared tvith tvhat is regarded 

 as normal, in amount and fluidity of the aZvine discharges ; 

 usually exhibiting as anatomical lesions only hypercemia and 

 turgescence of the onucous inemhixme, in exceptional instances 

 inflammatory changes. 



Pathology, a. Nature. — As with the opposite condition, 

 this may be looked upon as a distinct and pecuHar functional 

 disturbance, or as merely a symptom in the course of certain 

 and separable diseases. It is in the former light we now chiefly 

 regard it. 



In speaking of this fluid state of the alvine discharges it has 

 often been the custom to make distinctions, and to speak of it 

 under different names, according as its appearance has been 

 marked by differing clinical or anatomical features ; in this 

 way such terms have come to be employed as 'bilious diarrhoea,' 

 ' muco-catarrhal diarrhoea,' etc. However, it is probably per- 

 fectly sufficient for us, and equally conducive to the attainment 

 of our object, that we regard all these states of the intestinal 

 canal characterized by an increase in quantity and fluidity of 

 the material voided as cases of ' diarrhoea.' 



Indicative most frequently of functional disturbance of very 

 varied character, occasionally of peculiar structural changes, 

 diarrhoea is common enough in all animals, but is, when 

 appearing in these, severally of very varying importance. In 

 some, as the bovines, a continuance of a very lax state of the 

 bowels may be neither indicative of serious disturbance, nor of 

 immediate nor yet remote danger ; whereas a similar condition 

 in the horse is usually indicative of perverted function, and if 

 continued is likely to lead to evil consequences. 



When occurring in connection with some general and 

 specific diseases it is often critical, and a matter of much 

 moment ; when appearing as we now regard it, independent of 

 any systemic disease or extensive local change, as a mere fre- 

 quent discharge of liquid excrement alone and^unmixed with 

 disease-products, it is rarely of such serious import. 



6. Causation. — Resulting from increased peristaltic action, 

 excessive secretion, or from both combined, the immediate 



