Fistula. in a'no. No part of the body is more subject to abscesses than that immediately surrounding the lower part of the rectum: it is much exposed to pressure and other external injuries, which impede the free motion of the blood; and, in parts where the circulation is so languid, obstructions soon occur, and purulent matter is formed with little appearance of active inflammation. We sometimes find also a metastasis to this part; and there are anomalous cases of hectic which seem to originate from an affection of the liver, where this metastasis is not uncommon. As the skin is pretty thick around the rectum, the pus will insinuate itself amongst the soft neighbouring parts, and form sinuses, which degenerate into fistulae.

This kind of fistula is called complete when there is an opening into the gut, and another externally; incomplete when there is no external aperture.

The symptoms of the incomplete kind are analogous to those of the piles, and are difficultly distinguished from them. The complete kinds have generally callous lips, which, with the discharge, more readily points ou the nature of the case.

Abscesses in this part should be opened as soon as we find a fluctuation of matter, and by a large aperture, most effectually to prevent a return. In examining one of these fistulas, if the probe does not readily pass; warm milk may be injected into it, to see if any returns by the rectum, and of course to discover if the gut is perforated. When the probe is used for the examination, let the patient stand on the ground, with his feet pretty far asunder, and lean on the belly over a table: an assistant can then hold his buttocks asunder, that the operator may more readily introduce his finger into the anus before he examines the fistula with a probe If the fistula runs so deep that the finger introduced into the anus cannot easily reach the orifice, the cure is doubtful, and the attempt dangerous, on account of the haemorrhage from the vessels, which admit not either of compression or ligature. If a fistula hath been of long standing, in a bad habit, and the discharge is such as to weaken the patient, the operation should not be attempted, at least till the constitution is repaired; but if the patient is of a good habit, if the fistula returns; the operation may be repeated.

We have just remarked also that a fistula is sometimes connected with diseases of the liver or the lungs, and in these cases it appears to be a critical discharge. If any cough or hectic fever has preceded, the operation soon hastens the fatal termination. The hectic recurs with increased violence, the purulent expectoration is more copious, and the strength rapidly fails. The appearances which contraindicate the operation, are those only which are pulmonary; but the true hectic, viz. where the lungs alone are affected, seems seldom, if ever, to be attended with abscesses of this kind. Where an affection of the liver has preceded or accompanied the disease of the lungs, such dispositions are not uncommon, and the event is such as we have described.

Some authors have contended that all fistulae are critical, and we have sometimes inclined to that opinion; yet, as they may be sometimes safely cured, and the disease is inconvenient and distressing, if not acutely painful, should there be no other apparent disease, the operation may be attempted. If not advisable, country air, milk diet, a mildly tonic course of medicines, with gentle eccoprotics, will often relieve; and nature will sometimes complete the cure, or so far relieve the complaint as to produce no great inconvenience. See St. Andre on Fistula in Ano.

Dr. Monro's instruction we shall add: "Wherever the opening of the fistula is, if it hath any turnings where it reaches the gut, divide them, and make them straight, avoiding the sphincter. After this I attempt to promote incarnation, which might lessen the cavity, and by degrees fill it up, by injecting balsamic softening medicines; though sometimes a patient of a good habit may be cured by applying a poultice of bread and milk, and a digestive. If this fail, I endeavour to render the parts entirely callous and insensible, by injecting a mixture of lime water and brandy, with a little honey of roses, increasing the brandy and diminishing the rest, as the 4Q parts lose their sensibility, until at length I inject pure alcohol, which renders them quite insensible."

When the operation is performed, a probe pointed bistoury is to be passed into the fistula, and the finger into the rectum, to meet it. If the fistula is incomplete, the probe is sometimes passed through the gut, at its upper part, to render it complete; but this, we think, should be avoided. The sharp pointed bistoury is then passed along the other, and the sinus divided. In general, however, the probe is passed through the upper aperture, and bent down by the finger, when the sinus is cut through by the common scalpel. If the sinus goes beyond the reach of the finger, it should be divided only so far as the latter can extend; for beyond it the knife must not be trusted. As the external opening is usually on the outside of the rectum, the sphincter is commonly divided; but this occasions no inconvenience.

When the patient dreads the knife, it has been usual, in the complete fistula, to pass a silver or a leaden wire through the sinus, and to bend it from the upper orifice till it is again brought to the outside. The compression by this means destroys the life of the part; but the pain and irritation are too great to render it an eligible method.

It is styled an occult fistula when there is no external opening; and it is then difficult to determine whether the disease be really fistulous near the anus, or whether there be an abscess in the superior part of the intestine. The occult fistula is distinguished by a hardness, a painful swelling, and discoloration near the verge of the anus; while its existence is ascertained by matter being found mixed with the faeces, or following them. In the disease which is our present object, the matter more Frequently follows the feculent discharge. An opening is to be made in this case at the discoloured part, and the disease reduced to a complete fistula.