Megacolon presenting as anemia.

Clinical Images A 21-year-old man presented with symptoms of fatigue that had been progressing for several months. The patient had a history of depression and childhood constipation. Physical examination revealed conjunctival pallor, abdominal distention, and left upper quadrant firmness. Laboratory tests were positive for fecal occult blood test and revealed a serum hemoglobin level of 0.0048 g/dL. Abdominal ultrasonography (not pictured) showed leftsided hydronephrosis, and abdominal computed tomography (axial view, A; lateral view, B) revealed feces filling the rectosigmoid colon, with dilatation to 20 cm. A surgical evacuation was performed to remove this massive fecal impaction. After the surgical evacuation, scout radiography (C) showed continued gaseous distention. A postoperative colonoscopy revealed multiple bleeding ulcerations. Potential origins of this patient’s chronic constipation include idiopathic megacolon and Hirschsprung disease. Idiopathic megacolon is an uncommon cause of chronic constipation associated with atrophy of the muscularis propria, connective tissue, and enteric nervous system.1,2 This condition is commonly found in patients with intellectual deficits or psychological conditions.3 Although Hirschsprung disease is most often diagnosed in newborns and infants, mild cases may present in adolescents and adults as chronic constipation or malnutrition.4,5