Intramural fibroids grow within the muscular uterine wall. Submucosal fibroids bulge into the uterine cavity. Subserosal fibroids project to the outside of the uterus. Symptoms include heavy menstrual bleeding, menstrual periods lasting more than a week, pelvic pressure or pain, frequent urination, difficulty emptying the bladder, constipation and backache or leg pains.