If there is much resistance, it may possibly be caused by the stone having been caught in its longer axis, and this may be remedied by careful manipulation by means of the finger and forceps. If the stone is still too large to be extracted without greater force than is warrantable, there are still various expedients (see _infra_, pp. 265, 270). In most cases, however, the stone is removed rapidly enough by the single incision. The finger, or a sound, must then be introduced to feel if any more stones are present. The closed forceps make a very effectual instrument for this purpose. Much information may be gained from the appearance of the first stone, the presence or absence of facets. Its smoothness or roughness enables us to form a pretty certain opinion; yet the bladder should always be carefully searched; and if the stone has been friable or broken in extraction, should be washed out by a current of water. Where the calculi are very numerous, or where many fragments have separated, the scoop will be found useful, both for detecting and removing them. All the stones being extracted, there is in most cases little or no bleeding (see _infra_, Hæmorrhage). The tube already described may now be inserted and tied into the bladder. It may be retained for forty-eight or seventy-two hours, according to circumstances. Care must be taken lest it be closed up by coagula during the first hour or two after the operation. In children the tube is not necessary, and from their restlessness might possibly do harm, but in adults (though neglected by some surgeons) experience shows it is a valuable adjunct in the after-treatment. Having thus traced the course of an ordinary uncomplicated case of lithotomy by the lateral operation, a brief notice is suitable of some of the obstacles and difficulties, some of the dangers and bad results which may be met with, and the best methods of overcoming them. 1. _Large size of the stone_, as an obstacle to extraction. When, either from the enormous size of the stone, generally to be made out before the operation, or from some congenital or acquired deformity of the pelvis, it is obvious beforehand that the calculus cannot pass through the bony pelvis entire, a choice of two courses remains, either-- (1.) The high or supra-pubic operation (_q.v. infra_); or (2.) Crushing of the calculus in the bladder, and removal piecemeal. Instruments of great strength have been devised for this latter operation. The risk to the bladder is very great, and fragments are apt to be left behind; these are sure to form nuclei of new calculi. 2. _Peculiarities in the position or relations of the stone_ in the bladder:-- (1.) It may lie in a sort of pouch behind the prostate, and thus be out of the reach of the forceps. This may be remedied by the use of curved forceps, or, better still, by the finger in the rectum to tilt up the stone into the bladder.