Intussusception occurs when a part of the bowel invaginates into itself, causing venous and lymphatic congestion. Untreated, intussusception may lead to ischemia and perforation.
Intussusception most commonly occurs in infants and toddlers ages 6 to 36 months-old, and approximately 80 percent of cases occur in children younger than 2 years-old . Classically, parents report 15-20 minute episodes, during which their child seems acutely distressed, characterized by vomiting, inconsolable crying, and curling the legs close to the abdomen in apparent pain. They may also describe a “normal period” between episodes or offer a history that includes grossly bloody stools.
75 percent of cases of intussusception in young children have no clear trigger. Some evidence suggests that viral illness plays a role, particularly enteric adenovirus, which is thought to stimulate GI tract lymphatic tissue, in turn causing Peyer’s patches in the terminal ileum to hypertrophy and act as lead points for intussusception .
Approximately 10 percent of intussusceptions occur in children older than 5 years . Unlike their younger counterparts, these patients tend to present atypically, with pathologic lead points that triggered the event . The patient described above illustrates this well. At 10 years-old, he presented with peritonitis after his intussusception caused focal perforation, and had no prior history of colicky abdominal pain or bloody stools. Ultimately, he was found to have Meckel’s diverticulum. This is the most common lead point among children, but other causes include polyps, small bowel lymphoma, and vascular malformations .