Intussusception occurs when one segment of bowel invaginates into itself, most commonly at the ileocecal junction. It is the most common abdominal emergency and cause of intestinal obstruction in children less than 2 years of age. The precise cause is unknown in 75% of cases, although the incidence increases during seasonal viral gastroenteritis outbreaks. Adenovirus, bacterial enteric infections, Meckel diverticula, tumors, hematomas, and vascular malformations are thought to be potential lead points.
Patients typically present with sudden onset of intermittent severe episodes of cramping abdominal pain with inconsolable crying and drawing the legs up to the abdomen. Episodes usually occur at 15- to 20-minute intervals, but become more frequent as the illness progresses. Vomiting may follow painful episodes and can eventually become bilious. Initially, children appear normal between episodes, but progressive lethargy eventually develops. Bloody stools (occult or gross), a sign of intestinal ischemia, are seen in 50% of patients. A sausage-shaped mass may be palpated in the right upper quadrant. The differential diagnosis includes viral gastroenteritis, constipation, HPS, intestinal malrotation with volvulus, appendicitis, and meningoencephalitis.
Management and Disposition
If the diagnosis is uncertain, ultrasound is the imaging test of choice and often demonstrates the classic “coiled spring” or “bull’s eye” lesion. Plain x-rays obtained early in undifferentiated cases of abdominal pain may show a target or crescent sign, along with a paucity of cecal gas. Treatment begins with nonoperative reduction at an experienced institution with an air enema under fluoroscopic or sonographic guidance using pneumatic pressure to reduce the intussusception. The success rate is 80% to 85%. The risk of perforation is < 1%. As 24-hour recurrence rates are low (< 5%), admission to the hospital should be a case-by-case decision. Many patients can be discharged with strict return precautions after a 4- to 6-hour observation period if they are well appearing and tolerating a diet. Seek surgical consultation, as laparoscopy is indicated when nonoperative reduction is unsuccessful or incomplete.
Ileocolic Intussusception. Bloody “currant jelly” stools in a hypersomnolent 3-month-old female infant with transverse colon intussusception reduced by air enema. (Photo contributor: Donald H. Arnold, MD, MPH.)
Intussusception. The apex of the intussusception may extend through the anus mimicking rectal prolapse. It is distinguished from rectal prolapse by the separation between the protruding intestine and the rectal wall. (Photo contributor: Binita R. Shah, MD. From Shah B, Lucchesi M, Amodio J, Silverberg M. Atlas of Pediatric Emergency Medicine. 2nd ed. New York, NY: McGraw Hill; 2013: Fig. 10-3, p. 379.)
Currant jelly stools are seen in only 20% of patients and are a combination of blood and mucus indicative of sloughed intestinal villi.
The classic triad of pain, palpable ...