Intussusception occurs when part of the bowel telescopes into a distal segment, resulting in intestinal obstruction. If not diagnosed promptly, complications may occur, including arterial obstruction, bowel necrosis, perforation and even death. The initial presentation of intussusception is often nonspecific, limited to abdominal pain and vomiting. Early on, it easily can be misdiagnosed as gastroenteritis. Results of published studies indicate that clinical or epidemiologic factors predictive for this disorder include age less than one year, male sex, vomiting, abdominal mass, abdominal pain, rectal bleeding and lethargy. A diagnosis of intussusception can usually be confirmed by an air or liquid enema, or sometimes by ultrasound examination. Kuppermann and colleagues performed a retrospective study to identify and validate independent predictors of intussusception in young children by using multivariate statistical techniques.

The authors reviewed the charts of patients between the ages of one month and five years in whom contrast enemas were used to confirm or exclude the diagnosis of intussusception. Data obtained included patient age, sex and clinical history, physical examination findings and the results of plain abdominal radiographs. The radiographs were reviewed by a single pediatric radiologist who interpreted them as being not suggestive, moderately suggestive or highly suggestive of intussusception. Ten variables associated with intussusception that had been previously demonstrated in other studies were assessed. From these findings, a multivariate analysis was performed that included only findings seen in at least 75 percent of the patients' charts and indicated if the individual variable had a P value of 0.20 or less.

Over a five-year period, 115 children met inclusion criteria for the study. Of these, 68 (59 percent) had intussusception confirmed by contrast enema. Of the 10 variables selected, eight were noted in 75 percent of the cases. The data from these charts were then entered into a multiple logistic regression analysis. Initially, four independent predictors of intussusception were identified. These included a highly suggestive abdominal radiograph, rectal bleeding, male sex and a history of emesis. The authors then used a technique known as “bootstrap validation” and developed a clinical prediction model to further define the predictors of intussusception. When this model was complete, only the first three variables had significant predictive value (see the accompanying table).

The authors conclude that male sex, rectal bleeding and a highly suggestive abdominal radiograph are independent predictors of intussusception in children. Rectal bleeding and an abnormal radiograph are the two strongest predictors of this disorder. The presence of these two findings should encourage the clinician to proceed with an air or liquid barium enema. The absence of these predictors is associated with a low probability of intussusception.