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Intussusception is when the proximal portion of the intestine invaginates into the distal portion, causing an obstruction. Early in the process, lymphatic return is impeded, then as the edema and pressure increase, venous and arterial flow is compromised. Infarction of the collapsed bowel segment may occur. Intussusception usually occurs at age 3 months to 3 years, with a peak in infants <1 year old. In children <3 years old, it is generally idiopathic and possibly due to prominent lymphoid tissue in the intestine serving as a lead point. The majority are ileocolic, although may present anywhere along the lower gastrointestinal tract. In older patients, lead points include Meckel diverticula, polyp, tumor (lymphoma or hemangioma) or intramural edema and hematoma from Henoch-Schönlein purpura. Sites other than ileocolic are also associated with underlying pathology.
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Patients typically present with sudden-onset, severe, colicky abdominal pain at regular intervals and vomiting (initially nonbilious; may progress to bilious), bloody stool (“current jelly”—with mucus and gross blood or occult blood), and a “sausage-like” abdominal mass. Patients often curl up to guard the abdomen. Typically patients present without some, not all of the above, symptoms and they may be perfectly well between episodes. Lethargy and irritability may be prominent. The physical exam may show a “Dance sign” or an “empty right lower quadrant.”
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The differential diagnosis includes gastroenteritis, constipation, volvulus, toxin ingestion, or encephalopathy and any other condition that produces GI obstruction.
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Emergency Department Treatment and Disposition
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Obtain abdominal radiographs (supine, prone, and left lateral decubitus) for screening and to exclude free air. Obtain ultrasound for definitive diagnosis. Order complete blood count (CBC), serum electrolytes, blood type and screen, and consult surgery. Provide IV hydration and keep patients NPO (nothing by mouth). Attempt reduction of intussusceptions involving the colon with hydrostatic enema (air, barium, water). If reduction is not achieved after 3 attempts, consider repeated delayed reduction, or refer the child for operative reduction. Ileoileal intussusceptions either spontaneously reduce or require operative reduction. Free air on the radiograph or peritonitis is indication for immediate operative reduction. Whether or not to admit patients after successful reduction is controversial because of the potential for early recurrence.
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