Endometriosis is a condition in which tissue similar to the lining of the uterus, called the endometrium, grows outside the uterus. This tissue can grow on the pelvic organs, such as the ovaries and fallopian tubes, and can cause pain, especially during menstrual periods, sexual intercourse, bowel movements, or urination. Other symptoms may include heavy menstrual bleeding, infertility, fatigue, and diarrhea or constipation during menstrual periods. Endometriosis can be diagnosed and treated with the help of a healthcare provider, and treatment may involve medication or surgery