Positive guaiac and bloody stool are poor predictors of intussusception

Abstract

BackgroundCurrant jelly stool is a late manifestation of intussusception and is rarely seen in clinical practice. Other forms of GI bleeding have not been thoroughly studied and little is known about their respective diagnostic values. ObjectiveTo assess the predictive value of GI bleeding (positive guaiac test, bloody stool and rectal bleeding in evaluation of intussusception. MethodsWe performed a retrospective cross-sectional study cohort of all children, ages 1month-6years of age, who had an abdominal ultrasound obtained evaluating for intussusception over 5year period. We identified intussusception if diagnosed by ultrasound, air-contrast enema or surgery. Univariate and a multivariate logistic regression analysis were performed. ResultsDuring the study period 1258 cases met the study criteria; median age was 1.7years (IQR 0.8, 2.9) and 37% were females. Overall 176 children had intussusception; 153 (87%) were ileo-colic and 23 were ileo-ileal. Univariate risk ratio and adjusted Odds ratio were 1.3 (95% CI, 0.8, 2.0) and 1.3 (0.7, 2.4) for positive guaiac test, 1.1 (0.6, 2.1) and 0.9 (0.3, 3.0) for bloody stool, and 1.7 (1.02, 2.8) and 1.3 (0.5, 3.1) for rectal bleeding . ConclusionBlood in stool, whether visible or tested by guaiac test has poor diagnostic performance in the evaluation of intussusception and is not independently predictive of intussusception. If the sole purpose of a rectal exam in these patients is for guaiac testing it should be reconsidered.