Constipation on abdominal radiograph as potential risk factor for recurrent urinary tract infection development.

Background: To compare clinical history and measurements of fecal load on abdominal radiography (AR) in the prediction of urinary tract infection (UTI) recurrence in children.

Methods: We combined data from two multicenter longitudinal studies in which children less than 6 years of age with a first or second UTI were followed for recurrence of UTI. Two radiologists reviewed the scout abdominal radiographs of initial voiding cystourethrograms obtained at enrollment from children at two participating sites and measured stool visible in various parts of the colon. We examined how well clinical variables (e.g., voiding and bowel history, use of laxatives at enrollment) and measurements of fecal load predicted recurrence of UTI within 12 months of enrollment.

Results: One hundred and ninety-two children were included. On univariate analyses, age, vesicoureteral reflux (VUR), cecal diameter, rectal diameter, and total stool length on AR were associated with recurrence of UTI. After controlling for age, the odds of recurrent UTI in children with VUR at baseline was 3.85 (95% CI: 1.62, 9.14) higher than in children without VUR. Recurrent UTI was 2.57 (95% CI: 1.01, 6.55) times more likely in children with cecal diameter > 3.10 cm than children with lower cecal diameters; time to first recurrent UTI was shorter in children with elevated cecal diameters (p = 0.0023).

Conclusions: Cecal diameter on abdominal radiographs predicts UTI recurrence in children with a previous UTI. However, its accuracy is suboptimal to serve as a screening test. Accordingly, its routine use for this indication is not supported. If cecal diameter on an AR ordered for another indication is > 3.10 cm, then management of constipation could be considered.