Operation for Fistula in Ano

rowing and undermining the perineal and circumanal structures, for months and even years, before it is brought under the notice of the operating surgeon. For this reason it will be found that the fistula has in most case3 made its way as far as the external coat of the bowel; and this circumstance has suggested a mode of operating which I have now practised for several years without a single failure in several dozens of cases operated on. The object the surgeon has in view is to widen the outlet for a time, and to incapacitate the sphincter from acting; and tho operation usually recommended for effecting this purpose, is to pass a bistoury with, a properly made point through the track of the fistula, and to make the point of the bistoury meet the forefinger of either hand, passed through the natural opening ; when the knife and finger, having been placed in contact, are to be withdrawn together, dividing all the intervening structures down to the external anal aperture. This operation, which seems simple enough, is, however, in practice by no means easy ; in the first place there is danger of the knife breaking if the parts have been much condensed and thickened?an accident that I believe once occurred to the famous Liston ; ard in the second place, the difficulty of keeping the point of the bistoury and the tip of the finger in actual contact is greater than would be imagined. Again, the point of the bistoury may not be made to penetrate the extremity of the fistulous track?a proceeding that will necessarily endanger the success of the operation ; or, if pushed through, it may slide back, and may not again be made to pass through the original point of emergence; in which case, the fistula will not be laid open throughout its whole extent, and the surgeon's intention will in consequence be completely frustrated. As any one of the foregoing accidents may interfere with the success of the operation, I have been led to adopt a mode of