Small Bowel Obstruction-Intussusception

Small Bowel Obstruction from Intussusception

XR – Moderate diffuse dilation of small bowel dilation with paucity of colon gas consistent with distal small bowel obstruction.

CT – Axial and coronal reformat images show bowel within bowel in the low mid-abdomen consistent with intussusception.

Intussusception is the most common cause of small bowel obstruction in children. Intussusception is most common between 2 months and 3 years of age with the peak between 5 and 9 months. Most intussusceptions are related to lymphoid hyperplasia within the bowel wall or disordered peristalsis; occasionally pathologic lead points (Meckel diverticulum, duplication cyst, polyp, and lymphoma) or systemic disease (cystic fibrosis, Henoch-Schonlein purpura) are responsible.

Presenting symptoms are largely related to bowel obstruction and subsequent impaired venous and lymphatic drainage. This pathophysiology explains the classic clinical triad of colicky abdominal pain, vomiting, bloody-stool and palpable abdominal mass.

The diagnosis can be suggested by radiography although sensitivity and specificity are poor. Ultrasound is becoming the primary modality for diagnosis of intussusception with high sensitivity and specificity without exposure to ionizing radiation. Fluoroscopically guided hydrostatic or pneumatic reduction is attempted once the diagnosis is established (contraindications to image-guided reduction include peritonitis and free air; relative contraindications include high fever, leukocytosis, rebound tenderness, severe dehydration, and profound lethargy).

Applegate KE. Intussusception. Caffey’s Pediatric Diagnostic Imaging, 11th Ed. (2008).