Review Question - QID 103358

This patient with colicky abdominal pain relieved with flexion of the knees, currant jelly stools, and a target sign on ultrasound likely has intussusception. Approximately 75% of intussusception cases are idiopathic.

Intussusception occurs when a section of the small bowel telescopes into another part of the intestine; most commonly, the terminal ileum invaginates into the proximal large bowel. Intussusception is the most common cause of bowel obstruction in the pediatric population, and it typically occurs in patients between 3 months to 3 years of age. While 75% of cases are idiopathic, 25% are associated with a pathologic lead points in conditions such as Meckel's diverticulum, gastric polyps, intestinal lymphoma, or infections.

Martin et al. discuss Meckel's diverticulum, a congenital gastrointestinal tract abnormality. Meckel's diverticulum is a true diverticulum and often contains ectopic gastric tissue. Meckel's diverticulum can serve as a lead point and cause intussusception. Other complications of Meckel's diverticulum include intestinal obstruction, diverticulitis, hemorrhage, and perforation.

Rha et al. review the evidence regarding the association of the rotavirus vaccine with intussusception. When the first rotavirus vaccine was released, it was promptly removed from the market in the USA because of increased occurrence of intussusception. RotaTeq and Rotarix are two live oral rotavirus vaccines that are now being used. Surveillance data of these vaccines reveal that they do slightly increase the risk of intussusception.

Figure A reveals a target sign or donut sign on ultrasound which represents the telescoping bowel. Illustration A shows a diagram of the telescoping section of bowel and the consequent obstruction. Illustration B shows the finding of a target or donut sign on CT in a patient with intussusception.

Incorrect answers:
Answer 2-5: All of these are possible causes of intussusception; however, the most common cause is idiopathic.