within the abdominal cavity. Organs of the abdomen include the stomach, small intestine, colon, liver, gallbladder, spleen, and pancreas. However, the lowermost portion of the area described previously. is the pelvis, which contains the urinary bladder and rectum as well as the prostate gland in men, and the uterus, Fallopian tubes, and ovaries in women. Practically speaking, it often is difficult to know if lower abdominal pain is coming from the lower abdomen or pelvis.