Uterine prolapse is the protrusion of the uterus into the vagina. The uterus is usually located above the vagina, held by muscles and ligaments. Uterine prolapse is caused by these muscles and ligaments and are too weak to hold on to the uterus. Gradually, the uterus sags and moves out of its normal position, so it bulges into the vagina. in extreme cases The uterus is very dilated and protrudes outside the vagina in between the legs. The bladder, urethra, and rectum (the muscles that control bowel movements) may bulge out along with the uterus. Untreated prolapse can cause cervical ulceration. This increases the likelihood of infection or injury to other pelvic organs.