DILATATION AND INCISION.—This operation, if skillfully and carefully performed, I believe to be a radical and unfailing cure for the disease. The bowels should be cleared out by a dose of castor-oil and an injection; after which, under ether-anæsthesia, the sphincters should be dilated in the manner previously described. This being accomplished, and the ulcer properly exposed, a straight blunt-pointed bistoury (Fig. 12) should be drawn deeply across the surface, making a cut about an inch in length and a third of an inch in depth. Instead of the blunt bistoury, a sharp-pointed scalpel may be used (Fig. 13). It should be entered at the margin of the anus, passed under the ulcer, and made to protrude above the ulcer, the overlying structure being then divided from without inward. [Illustration: Fig. 12—Blunt-pointed Bistoury.] [Illustration: Fig. 13—Sharp-pointed Scalpels.] The subsequent treatment consists in keeping the patient in the recumbent position, and in the use of a little opium to confine the bowels. After three or four days a laxative may be given, from which time daily alvine movements should be secured. In seven or eight days the patient can begin to move about; but for at least two weeks he should avoid standing long on the feet. No dressing is required further than bathing the parts with a little warm water and carbolic acid soap, to remove any offensive discharges. For the same purpose, peroxide of hydrogen may be employed. THE SUBCUTANEOUS DIVISION OF THE SPHINCTERS, as recommended by some authors for the cure of fissure, is not a satisfactory method, and is mentioned here solely to condemn it. It is not only uncertain in its results, but is also painful, and in more than one instance has been followed by abscesses. ----- Footnote 25: _Op. cit._, p. 189. Footnote 26: _Op. cit._, p. 215. Footnote 27: W. P. Agnew, M.D., "Diagnosis and Treatment of Rectal Diseases," second edition, 1891, p. 97. Footnote 28: _Op. cit._, p. 111. Footnote 29: _Op. cit._, p. 214. Footnote 30: _Op. cit._, p. 215. Footnote 31: _Op. cit._, pp. 75-76. Footnote 32: _Op. cit._, p. 221. ------------------------------------------------------------------------ Part 2.—Fistula in Ano. * * * * * CHAPTER I. RELATIVE FREQUENCY—AGE AND SEX AFFECTED—ETIOLOGY—CLASSIFICATION. FISTULA IN ANO which is not due to ulceration and perforation of the rectal wall from within is the result of a previous abscess. Such an abscess forms in the ischio-rectal fossa, and, although opened early by a free incision even before the cavity becomes distended with pus, it frequently fails to heal. It may fill up and contract to a certain extent, but it does not become entirely obliterated; a narrow track remains, which constitutes the affection designated fistula in ano.