PROLAPSUS ANI. 411 



that this speedily opposes all attempts at return, should the 

 animal make any ; though, in truth, his efforts in general 

 have the effect of straining more gut out, and with his strain- 

 ing, in some cases, lacerating the membrane, and thus aug- 

 menting, instead of diminishing, the evolution, while it gives 

 rise to pain which was not felt before. In this manner arises a 

 large, sometimes enormous, rotund, red, rugose, efflorescence, 

 consisting of cylinders of mucous membrane, having an 

 aperture closed, through constriction, in its centre, though, 

 while open, issuing a mucous and sanious matter, especially 

 at such time as the animal is straining afresh. The cir- 

 cumflex action of the sphincter ani around the neck of the 

 swelling, together with its distension with gas and the action 

 of the air upon its surface, all add to its increase of volume, 

 and change of colour, as well as to augment the pain ; while the 

 power at the same time enhances the difficulty of any effort 

 the practitioner may make towards effecting a return of the 

 protruded gut. With its augmentation of volume comes a 

 deepened redness, turning, through the constriction of the 

 sphincter, to a darker and even purple hue, the membrane 

 becoming, at the same time, inflated and oedematous ; and 

 gradually changing its colour from red to yellow and brown, 

 though still having a humid shining aspect, now becomes 

 glairy from albuminous secretion, which is not only mucous 

 but at times purulent. 



Causes. — These may be summed up in irritation, either 

 direct or sympathetic, of the mucous membrane lining the 

 anus and rectum. It is possible that prolonged constipation, 

 by giving rise to violent straining efforts at expulsion of 

 dry and hardened fa3ces, might bring it on ; or even the 

 strains of parturition. The action produced by excessive 

 purgation may cause it ; more especially irritation of a me- 

 chanical kind, arising from direct injury to the membrane or 

 rectum during the operation of raking or manual exploration 

 of the gut or of clystering. It may prove an accompaniment, 

 of an enteritic, colicky or diarrhoeal condition of bowel. It 

 is possible it may ensue on nicking ; though I never knew it 

 to follow that operation — violent struggles indeed of any kind. 



