Scoring system to evaluate meaningful fecal impaction in patients with lower urinary tract dysfunction with simple radiography (KUB)

Purpose: The management of bowel bladder disorder (BBD) has only been indicated for subjective constipation without objective evidence. We attempted to highlight the radiological findings in patients with BBD and construct a scoring system to identify patients with BBD prior to treatment. Materials and Methods: Forty-five patients with lower urinary tract dysfunction (LUTD) received polyethylene glycol for 2 months before bladder medication for LUTD. Based on partial response to LUTD following treatment, we divided the patients into LUTD-fecal impaction (FI) and LUTD not attributed to FI (LUTD-NFI) groups. Pre/post-treatment kidney, ureter, and bladder (KUB) were compared with respect to several radiographic parameters. Items with significant changes after treatment were included in the scoring system. The accuracy and inter-rater agreement were also evaluated. Results: Cecal dilation, descending colon dilation, fecal quality, and overall haziness were found to undergo significant changes after laxative treatment. We assigned 0 to 2 points for each item, with a total score of 8. Receiver operating characteristic curve analysis revealed a cutoff value of 5 between LUTD-FI and LUTD-NFI, with 79% sensitivity and 88% specificity. The scoring system was instructed to six doctors who were unaware of it and was then tested on previous patients, which showed a substantial concordance rate (κ=0.79, p<0.05). Conclusions: Fecal scoring system based on KUB was beneficial in identifying children with LUTD attributed to FI. This may provide an opportunity to obtain objective FI data as an alternative to subjective assessment of constipation.