From wikipedia -
Important organs of the left lower quadrant include part of descending
colon, sigmoid
colon,
left ovary and Fallopian tube or
left uterine tube.
If abdominal pain or signs of peritonitis are localised in the left lower quadrant, the suspicion is increased for such conditions as colitis, diverticulitis, ureteral colic or pain due to ovarian cysts or pelvic inflammatory disease. Examples of tumors in the left lower quadrant include colon cancer or ovarian tumor.