Fetal bowel dilatation is characterized by fluid-filled intestinal loops which measure at least fifteen millimeters long or seven millimeters in diameter. Ultrasonographic image of dilated fetal bowel is a sign of intestinal mechanical or functional obstruction and its prevalence will depend on the underlying condition: bowel atresia or stenosis, malrotation with volvulus, meconium ileus, total colonic aganglionosis, and meconium plug syndrome. The etiology of fetal bowel dilatation is a difficult prenatal diagnosis since ultrasound has limited accuracy for bowel evaluation.