The diagnosis of recto-vaginal fistula is easy ordinarily, since we can readily examine the recto-vaginal septum. The finger may usually detect even a small fistula when its borders are thickened. The patency of the fistula may be determined by one finger in the rectum, and another in the vagina. In case of very small fistulm the sound is of assistance.
If the matter is still in doubt, injection of fluid into the rectum will settle it. Further still, the posterior vaginal wall and the anterior rectal may be exposed by the speculum As for differential diagnosis, the only thing which might simulate the symptoms of fistula is the passage of air and of ffeces into the vagina from without. (See under Foreign Bodies in the Vagina, for a case in point.) • The treatment of a recto-vaginal fistula can only be effective when it is possible to control the ulcerative process, and to cause regular cicatricial contraction of its borders, and when the size of the defect permits of closure. At the outset, then, a good result is rarely possible in ease of carcinomators fistulFe or those complicated by a chronic ulcerative pro Cess. Fortunately, the reverse holds true for the large majority of recto vaginal fistulfe, and the results of treatment are not unfavorable, although it cannot be stated that their cure by operation is certain. The tendency which we have noted towards shrinkage, and the not infrequent instances of spontaneous cure, exemplify this statement, especially when the fistula is of rather recent date. In case of fistuhe following on labor, they should be left alone for six weeks before an attempt is made at artificial repair. Separation of the recto-vaginal wall, of recent traumatic origin, should, when possible, be repaired by suture. Defects the result of ulcerating processes should. be incited to cicatrization of the borders.
For this purpose rest and cleanliness, irrigation twice or thrice daily, and small lukewarm enemas, suffice. Tampons, carbolized or glycerinized, should be inserted into the vagina; where the ulcers are not healthy looking, antiseptic applications may be made per vaginana, with occasional cauterization. In case of chronic recto-vaginal fistula? the treatment con sists either in cauterization or in denudation followed by suture.
Cauterization is applicable alone to small fistula3, the size of a pea even, and results more frequently in cure than do similar vesico-vaginal fistulte.
Since the object is to destroy entirely the cicatricial tissue along the edges, and to cause the subsidence of fungous granulations, the e,austic must be applied to both openings of the fistula. Lunar caustic, less frequently fluid caustics (nitric acid, tincture of cantharides, liq. hydr. nitr., etc.), are used. After cauterization the immediate effect is often a slight en largement of the fistula, and later marked shrinkage sets in. It is ad visable not t,o cauterize oftener than once in eight days. In cicatricial &tulle the cautery acts more energetic,ally. R. Liston used with success the glowing wire. Dieffenbach laid stress on the necessity of causing concentric shrinkage. It was his custom to touch the rectal side of the fistula with nitrate of silver, and then for days afterwards he applied the actual cautery to the vaginal opening and the fistulous tract as well. Both vagina and rectum were then filled with charpie, and mild or strong injections, according to the case, were administered occasionally. Lat terly, frequent application of the actual cautery has been rightly con demned by Hegar and Kaltenbach, since the cicatricial tissue interferes with subsequent denudation and union by suture. In general, the small oblique fistulte are best suited for cauterization. Small thin-walled fistulte with sharp cicatricial borders are rather made larger than smaller by cau terization.
The method of denudation and suture has the advantage that it is ap plicable to large and deep-seated fistulx, but the technique, even as in case of other vaginal fistula3, is difficult, and not infrequently the opera tion fails even in skilled hands. The reasons for failure depend not alone on the contact of fa.cal masses with the waund, and the varying traction according to the amount of gas in the rectum, and the muscular con traction, but also, in particular, on the difficulty in reaching the fistula when it is deep-seated, on the thinness of its walla when it is seated in the middle segment of the recto-vaginal segment, and lastly, in case of fistulte on the boundary between the rectal and perineal segments, on the unequal thickness and tension at the upper and the lower borders. Further still, the borders of the thin and loose rectal mucous membrane readily prolapse into the wound if it be not perfectly secured by suture, and then again the sutures readily tear out.