There are a number of medical conditions that have symptoms similar to that of ovarian cancer, many of which are far more common. These include: Appendicitis Cystitis Irritable bowel syndrome (IBS) Ectopic pregnancy Endometriosis Ovarian cysts Pelvic inflammatory disease (PID) Polycystic ovary syndrome (PCOS) Premenstrual syndrome (PMS) Urinary tract infection (UTI) Uterine fibroids Other cancers of the abdomen or reproductive tract