186 



ANUS. 



occur, then, that hardened faeces impacted in 

 the rectal pouch, which is above this point, may 

 assist in obstructing the more free flow of 

 blood, and thus encourage the enlargement 

 of these anal veins, and the same effect may 

 be still further induced by the muscular pres- 

 sure employed in defaecation ; in support of 

 this view we find that children are almost free 

 from this varicose condition of these veins, 

 unless under peculiar circumstances ; and in 

 the adult it usually occurs in those of con- 

 stipated habit of bowels ; it is also relieved or 

 removed by attention to their functions. The 

 true haemorrhoidal tumours, external as well as 

 internal, must be regarded as essentially dif- 

 ferent from a varicose condition of the anal 

 veins, although they are often connected with 

 the latter, and it must be admitted that in 

 some cases they may owe their origin in a great 

 measure to venous dilatation. Varices of the 

 anal veins are simple dilatations either of a 

 trunk or of some of the branches of these 

 vessels ; their cavity is continuous with that of 

 the vein, and freely communicates with it, 

 and pressure on the varix empties it of its 

 contents ; its tunics are the venous coats and 

 the membrane of the intestine; whereas hoemor- 

 rhoidal tumours are wholly distinct from the 

 veins, and are either simple cysts, lined by 

 a smooth membrane, or they are composed 

 of a spongy cellular texture, not unlike the 

 erectile tissue. This latter is usually the con- 

 dition of recently formed haemorrhoids, whereas 

 in those of long standing the single or divided 

 cyst is the ordinary structure ; this cyst will be 

 found to contain a little blood, partly fluid 

 and partly coagulated ; and when the internal 

 surface is minutely examined, one or more 

 tine pores will be visible, the orifices of ca- 

 pillary vessels, through which warm water, 

 if steadily injected by the inferior mesenteric 

 artery, will exude on the surface. In the cellular 

 or more recent haemorrhoids the texture ap- 

 pears very vascular, soft, and spongy, as also 

 the surface of the tumour, from which blood or 

 serum will sometimes exude during life. 

 These cellular haemorrhoids in time become 

 circumscribed, the cellular texture becomes 

 more or less perfectly absorbed, and the cyst- 

 like structure becomes more developed ; how- 

 ever a very recently formed haemorrhoid may, 

 and sometimes does, present a distinct cyst or 

 cavity, as may be readily conceived when we 

 consider the process whereby these tumours 

 come to be developed, which, as far as our 

 observation extends, is as follows : from con- 

 tinued irritation from any exciting cause, such 

 as disease of the intestine or anus, worms, or 

 from a local plethoric condition, spontaneous, 

 as far as we can know, the capillary circulation 

 is increased in the loose submucous tissue in 

 this region, a small quantity of blood, or 

 lymph, or serum, is effused into it, perhaps 

 from the rupture of some small vessels, or 

 exhaled from their dilated extremities. A 

 slight degree of inflammation attends this con- 

 dition : the part affected, that is, the cellular 

 tissue, becomes more highly organized, thick- 

 ened, vascular, and spongy. After some time, 



this increased vascular action subsides, and in 

 process of time the whole may nearly dis- 

 appear, but in general a part of this more 

 highly organized spongy tissue remains, it 

 being fully supplied with nourishment; the 

 absorbents in due course modify its appear- 

 ance ; the surrounding thickening is removed, 

 as also some portion of the cellular mass, 

 and thus the formation of the hcemorrhoidal 

 cyst is completed. A structure like this, con- 

 nected with the capillary system, must be 

 influenced by the same causes as can affect 

 the latter ; thus irritation local or general, me- 

 chanical injury, or general or local plethora 

 are all capable of exciting increased action in it, 

 and of inducing all those symptoms and changes 

 which are so well known to attend during 

 haemorrhoidal inflammation. 



Fistula in ano is a disease of such very fre- 

 quent occurrence, and so well understood and 

 described by every surgical writer, that it is 

 scarcely necessary to do more than allude to 

 it in this place : strictly speaking it is not a 

 disease of the anus, as that opening is in 

 general totally unaffected, except as regards its 

 functions : it should rather be regarded as a 

 disease of the anal region. There is one form 

 of fistula in ano, however, which is seated on 

 the very confines of this opening ; it is trou- 

 blesome and distressing, attended with heat, 

 itching, and excoriation, pain during defaeca- 

 tion, and constant purulent or sero-purulent 

 discharge: without due attention it may be 

 overlooked by the surgeon, as the orifice is so 

 close to the anus as to be concealed by the 

 natural rugae, and so small as only to admit a 

 lachrymal probe ; the sinus is not more than 

 an inch or half an inch long; its internal 

 opening is on the very edge of the anus, the 

 whole is immediately under the skin, and does 

 not involve any other structure ; it is not pre- 

 ceded by regular abscess, neither does it or the 

 treatment necessary for its cure involve the 

 sphincter or any other structure, except the 

 fine integuments ; it most probably originates 

 in irritation of some of the anal sebaceous 

 follicles, and sometimes two or three of such 

 fistulae may exist at the same time. 



The true or deep fistula in ano has its origin 

 in deep-seated abscess commencing close to 

 the rectum, or in the centre of the ischio-rectal 

 space of either side : when in the former, 

 some mechanical irritant or some disease of 

 the intestine may have been the cause or 

 origin of the abscess ; when in the latter, it 

 often arises without any obvious reason, but 

 frequently appears to have been connected 

 with some peculiar delicate or morbid con- 

 dition of the constitution. All abscesses in 

 this situation do not necessarily end in fistula ; 

 if they have been small, superficial, opened 

 early, and treated judiciously, they may be 

 healed as perfectly as abscesses in any other 

 situation; but when deap-seated, of slow 

 growth, and long continuance, and when de- 

 pending on some deep-seated mechanical irri- 

 tant or on constitutional causes, then the ab- 

 scess usually attains considerable size, and 

 having opened either into the rectum or through 



