PROLAPSE OF THE RECTUM AND ANUS. 
343 
punctured from without. In the above described case, Moller opened 
the abscess with a bent trochar (Flourant’s), and gave exit to about 2 
litres of thick offensive pus, containing fragments of necrotic tissue. 
As the abscess had refilled next day, the opening was lengthened with 
a button-pointed tenotome, introduced into the rectum with its cutting 
surface covered by the hand. Complete recovery took place in three 
weeks. 
After incising the abscess, the cavity must be carefully washed out with 
a strong stream of disinfecting material, so as to remove necrotic portions 
of tissue, and precautions taken for securing drainage of pus. Relapses, 
however, are common; in a case described by Verlinde pus burrowed 
downwards as far as the Achilles tendon ; nevertheless, the animal eventu¬ 
ally recovered. 
Y.—PROLAPSE OF THE RECTUM AND ANUS (PRO¬ 
LAPSUS RECTI ET ANI). 
Permanent protrusion of the mucous membrane of the rectum through 
the anus is described as prolapsus ani. As the membrane appears after 
each act of defecation, prolapsus ani really consists only in the abnormal 
continuance of a physiological condition. This protrusion of the mucous 
membrane is most distinctly seen in horses, and in them prolapsus 
ani is rather frequent, but it also occurs in dogs and other domestic 
animals. 
When not merely the mucous membrane but the entire intestinal 
wall passes the anus, the condition is termed prolapsus recti. The 
posterior end of the bowel can only pass the anus after rupture of the 
periproctal connective tissue, but those portions of bowel normally 
clothed with peritoneum sometimes pass through the pelvic portion and 
anus, after becoming invaginated in the last part of the rectum, con¬ 
stituting a third condition—prolapse with invagination. We therefore 
distinguish— 
(1.) Prolapsus ani. 
(2.) Prolapsus recti. 
(3.) Prolapsus recti cum invaginatione. 
Prolapse of the anus and of the rectum generally results from severe 
diarrhoea, particularly if accompanied by tenesmus. The disease is 
favoured by weakness, with relaxation or paralysis of the sphincter ani. 
It is commonest in young animals, but in swine it also occurs at a 
later period. 
As a rule, the immediate cause is increased abdominal pressure, 
though inflammatory swelling of the mucous membrane of the rectum 
may cause prolapse, and both these have been seen after use of irritant 
