A mass of dry, hard stool that cannot pass out of the colon or rectum. Fecal impaction may be caused by using laxatives too often, using certain types of pain medicines, little or no physical activity over a long period, diet changes, or constipation that is not treated. Signs and symptoms may include being unable to have a bowel movement, pain in the abdomen or back, problems urinating, and nausea and vomiting. Fecal impaction may also cause problems with circulation, the heart, or breathing.