OPERATIVE TREATMENT.—In the more severe cases local treatment will fail to effect a cure, and operative interference will be necessary. There are three methods of repute to be considered in this connection: (1) _forcible dilatation_; (2) _incision_; (3) _a combination of these two procedures_, dilatation and incision. FORCIBLE DILATATION.—This is the operation recommended by Récamier, Van Buren, and others. It consists in introducing the two thumbs into the bowel, back to back, and then forcibly separating them from each other until the sides of the bowel can be stretched as far out as the tuberosities of the ischia. It is essential to place the ball of one thumb over the fissure, and that of the other directly opposite to it, in order to prevent the fissure from being torn through and the mucous membrane being stripped off. As pointed out by Allingham,[32] it is well to repeat the stretching in other directions until the entire circumference of the anus has been gone over. In this manner, by careful and thorough kneading and pulling of the muscles, the sphincters will be made to give way, and will be rendered soft and pliable. This procedure should always be done with the patient thoroughly under the influence of an anæsthetic, and should occupy at least five or six minutes. This operation is perfectly safe, but, as it is no less severe than the operation by incision, and as in some cases it fails to effect a cure, I can see no advantage in adopting it instead of the more satisfactory and always successful plan of treatment by combined dilatation and incision. It may be found preferable in some cases on account of the prejudice of patients against the use of the knife. INCISION.—A fissure can be cured by this method, by making an incision through the base of the ulcer and a little longer than the fissure itself, so as to make sure of severing all the exposed nerve-filaments. The cut should divide the muscular fibers along the floor of the ulcer. In a fair proportion of cases this operation will meet with success, but it is not so certain and radical as the operation next to be described. It has the advantage over the other operations, however, of being nearly or entirely painless under local anæsthesia produced by cocaine, and therefore, when general anæsthesia is contra-indicated, or is refused by the patient, this method is worthy of a trial.