Contraction of the anus also frequently ex ists without any fissure ; sometimes it is con genital, sometimes it appears in the adult; the pain and other symptoms are nearly analogous, and as severe as in the case of fissure ; the examination by the finger however does not detect one part to be more painful than another, as is the case in that disease ; and this is almost the only symptom distinguishing these two affections.
The term hemorrhoid has been applied by writers, practitioners, and invalids to any con dition of the rectum and anus in which a discharge of blood takes place. It is, how ever, more correctly applied to the small tu mours which are frequently seen at and very close to the inner border of the anus or even occupying the very aperture, also to somewhat similar productions situated within the rectum, at the distance of one, two, or even three . inches above the anus. From such tumours occupying these different positions, they have been arranged by all writers into external and internal the latter are very im portant and demand the close attention of the surgeon, both as to their pathology and sym ptoms, as being frequently obscure and liable to be mistaken not merely for the ordinary diseases of the anus, such as fissure, blind internal fistula, &c., but also to be confounded with a varicose condition of the veins of the rectum, which is by no means an uncommon condition, or with those vascular tumours which are productions of the mucous mem brane occasionally protruding at the anus, that have been already noticed, and are of a wholly different character from -true hm morrhoidal tumours, or with the protrusions of the mucous membrane itself, the effect of the relaxation of its cellular connections. As the full consideration of this important branch of pathology belongs to the article on the mor bid anatomy of the rectum, we shall here con fine ourselves to a few observations on external haemorrhoids and analogous tumours.
External hemorrhoids appear at the border of the anus as small bluish tumours, the .colour however varying according to the con dition of the tumours, being sometimes of a dark and deep red or black, at others pale and almost white; in size they vary from a grain of small shot to a large cherry; they are some times full and almost bursting, at others they are soft like a flaccid nipple, empty or with ered ; they are covered on the anal side by the delicate cuticle which is smooth and glossy, and on the outer side by the common integu ment; when small, they are moveable and can be distinctly felt to be in the subcutaneous cellular tissue ; when large and tense, they ap pear more connected with the skin itself; an attentive examination can always distinguish between these and the several excrescences, vegetations, or condylomata, which have been already mentioned as the effects of syphilis, as also the folds or crests of integument and membrane which are found so fre quently prolonged from the border of the anus. These tumours remain in many persons for years free from pain, and productive of Jittle, if of any, inconvenience; occasionally, however, and periodically in some, they en large, inflame, and interfere with the functions of the anus, and by sympathy engage the ad jacent organs, and are relieved either by a copious discharge of blood, or by suppuration, .or by the interference of art.
The liability of the veins immediately about the anus to varicose enlargement appears in some measure founded in anatomical structure. If we inject the intestinal veins in the adult with wax injection, we shall often find a little above the anus, just where the skin and mu cous membrane unite, a sort of constriction on the vessels ; the veins appear larger imme diately above it, and again below it, and many of the branches in the venous plexus around the anus appear to be enlarged, while in the very spot or circular line alluded to, the vessels appear to be compressed. It may
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 defmcation ; 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 hmmorrhoidal 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 hmmor 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 fine 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 formed hzemorrhoid 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 hmmorrhoidal 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 hzemorrhoidal inflammation.