Congenital anomalies of the small intestine, colon, and rectum

Congenital anomalies of the gastrointestinal tract are a significant cause of morbidity in children and, less frequently, in adults. These abnormaliti es include developmental obstructive defects of the small intestine, anomal ies of the colon, anomalies of rotation and fixation, anorectal anomalies, and intestinal duplications. Neonates with complete high intestinal obstruc tion do not usually require further radiologic evaluation following radiogr aphy, whereas those with complete low obstruction should, undergo a contras t material enema examination. An upper gastrointestinal series must be perf ormed in all patients with incomplete intestinal obstruction because manage ment is different in each case. In low intestinal obstruction, ultrasonogra phy (US) may help differentiate between small bowel obstruction and colonic obstruction. In addition, US can help correctly identify meconium ileus an d meconium peritonitis and is useful in the diagnosis of enteric duplicatio n cysts. In malrotation and anorectal anomalies, computed tomography (CT) a nd magnetic resonance (MR) imaging can provide superb anatomic detail and a dded diagnostic specificity. Intestinal duplications manifest as an abdomin al mass at radiography, contrast enema examination, or US. At CT, most dupl ications manifest as smoothly rounded, fluid-filled cysts or tubular struct ures with thin, slightly enhancing walls. At MR imaging, the intracystic fl uid has heterogeneous signal intensity on Tl-weighted images and homogeneou s high signal intensity on T2-weighted images. Familiarity with these gastr ointestinal abnormalities is essential for correct diagnosis and appropriat e management.