Validation and clinical utility of a bowel habit questionnaire in school-age children

The aim of the study was to validate a brief Bowel Habit Questionnaire (BHQ) with prospectively obtained data from a 14-day diary and to determine whether the BHQ predicts the development of medically significant constipation (MSC) during the following year.

The BHQ was distributed to parents of children ages 5 to 8 years during health supervision visits. Both the BHQ and subsequent diary were scored to indicate constipation if at least 2 of the following were reported: infrequent bowel movements, stool accidents, straining, avoidance, discomfort with defecation, or passing large stools >25% of the time. One year later, the BHQ was repeated to assess for MSC, defined as medical encounters about constipation or use of enemas, suppositories, laxatives, or stool softeners.

MSC was reported for 57 (13.7%) of 416 children on the first BHQ. Paired BHQ and diary data were obtained for 269 children; 54 (20.1%) had diary scores indicating constipation. BHQ had a sensitivity of 59.6% (95% confidence interval [CI] 46.7%-71.4%) and a specificity of 82.6% (95% CI 77.0%-87.1%). One year later, 11 children (5.2%) had developed new-onset MSC; 7 (63.6%) of these children had initial BHQ scores of at least 2. Positive and negative predictive values for MSC were 19.4% (95% CI 9.8%-35.0%) and 97.7% (94.2%-99.1%), respectively.

Parents often do not recognize constipation in young school-age children and most constipated children remain untreated. A brief screening questionnaire in this population proved to be valid but only moderately sensitive; efforts to improve sensitivity are needed before recommending it for routine use.