Thus, when a fistula is associated with a stricture of the rectum of a malignant nature, any operative interference on the former lesion will be out of the question. If it is a simple stricture and its existence be not recognized, or if it be left untreated, any operation performed on the fistula will fail to effect a cure.
Treatment by Incision.—In a large majority of cases of fistula in ano, the operation which is sanctioned by experience as the most prompt and certain at the same time that it is the safest in its results is to lay open the sinus into the rectum, dividing with the knife all the tissues intervening between its cavity and that of the bowel. Figs. 28, 29, 30 and 31 represent useful forms of knives for incising a fistula.
The preparation of the patient consists in having the bowels moved by means of castor oil or some other mild cathartic on the day preceding the operation, and on the morning of the operation the lower bowel should be evacuated by means of an enema.
Fig. 28—Blunt-pointed Knife.
Fig. 29—Curved Knife, useful in certain fistulous cases.
Fig. 30—Gowlland's Bistouries.
