What causes women pain in lower left abdomen?

Many possibilities.. Finding out the cause of abdominal pain is like solving a mystery: we collect clues from one's symptoms, history, examination+/- tests. Therefore, a "hands-on" eval is critical. In general, causes of left lower abdominal pain can include irritable bowel, diverticular disease, endometriosis, ovarian cysts, intestinal or gynecologic cancers, urinary tract infections, etc...