The uterus may be forced back into a post-normal location by the presence of a tumor in front or by the distended bladder, or it may be drawn back and fixed by peritoneal adhesions. Retro-location is liable to induce vesical irritation by putting the vesico-vaginal wall on the stretch and thereby dragging on the neck of the bladder. This intractable symptom is sometimes relieved by Emmet's buttonhole operation of urethrotomy, for an account of which see section on Anteflexion. This operation would obviously be applicable also for the relief of the same symptom when caused by ascent of the uterus. Ante-location of the Uterus. The causes of this displacement are similar to those which produce retro-location; they are--distension of the rectum, post-uterine hæmatocele, post-uterine tumors, and peritoneal adhesions. Ante-location often causes vesical irritation, consequent upon the invasion by the uterus of that space which belongs to the bladder. Lateral Locations of the Uterus. The entire uterus is often displaced to the right or the left by a tumor or by an inflammatory exudate. The latter occurs as a product of {154} cellulitis, usually in the left broad ligament, and crowds the organ toward the opposite side of the pelvis. After resolution the ligament, shortened by inflammatory contraction, draws the uterus to the affected side and fixes it there. Lateral displacement from this cause often accompanies laceration of the cervix, the cellulitis having occurred on the side corresponding to the laceration. Descent or Prolapse of the Uterus. The nature of this displacement is clearly indicated by its name. It is convenient to distinguish three degrees of descent: In the first the organ is displaced downward and forward until sufficient space has been gained between the cervix and the sacrum to permit the body to turn back into extreme retroversion; in the second the cervix descends to the vulva; in the third the uterus protrudes partially or wholly through the vulva, constituting a condition sometimes called procidentia. ETIOLOGY AND CLINICAL HISTORY.--Descent may be the result of any or all of the following causes: I. Pressure from above; II. Weakening of the supports; III. Increased weight of the uterus; IV. Traction from below. Either of the above conditions being the primary cause, the others singly or combined may result. I. Pressure from above may depend upon the presence of a pelvic or abdominal tumor, ascites, fecal accumulations, tight or heavy clothing, etc. II. The uterine supports may be weakened and relaxed in consequence of subinvolution, senile atrophy, abnormally large pelvis, increased weight of the uterus, pressure from above, traction from below, etc. III. Increased weight of the uterus may be caused by congestion, subinvolution, hypertrophy, hyperplasia, pregnancy, fluid in the endometrium, uterine tumors, etc.