Intussusception is the most common cause of bowel obstruction in the under 2 years/age patient and 95% of intussusceptions are ileocolic.

Patients present with intermittent abdominal pain and may present with vomiting and bloody stools as well. In the under 2 yr old patient, the cause is almost always idiopathic.

Beyond that period, lead points are common.

    Colocolic intussusceptions are rare in children and are most commonly secondary to juvenile polyps.

Lead points may also include Meckel’s diverticulum, neoplasms such as lymphoma, intestinal duplications, mucosal hematoma such as in Henoch-Schoenlein purpura, inflammatory bowel syndrome, post-operative conditions, angioneurotic edema(may be recurrent), trauma, leukemia, Peutz-Jaeger’s syndrome and hemolytic uremic syndrome.

   Diagnosis can be made rarely on plain film by “mass in gas” appearance, on ultrasound with the swirled sign of alternating sonolucent and hyperechoic layers of bowel.

 Transverse Ultrasound:

Hypoechoic outer rim and central echogenic core, doughnut sign

 Longitudinal:

Hyperechoic center - tubular shape in continuity with intestinal lumen on each side by hypoechoic layer - sandwich or pseudokidney sign or with enema (coil spring).

Air enema reduction is the preferred initial therapy, but endoscopy with biopsy or removal of the mass or if needed, surgery should follow in all cases of colocolic intusussception due to the likelihood of presence of a lead point.

Take Home Message: 

Mnemonic for acquires small bowel obstruction:

AAIIMM 

A-Appendicitis

A-Adhesions

I-Intussuception

I-Incarcerated inguinal hernia

M-Malrotation with midgut volvulus

M-Miscellaneous (Meckel diverticulum, duplication, ingested foreign body)