Slow transit constipation and lower urinary tract dysfunction.
INTRODUCTION
Many theories have been proposed for the coexistence of constipation and lower urinary tract dysfunction (LUTD), such as bladder compression from a distended rectum and stimulation of sacral reflexes from a full rectum. In these cases, successful treatment of constipation should result in resolution of bladder symptoms. Some children have refractory constipation and others respond well to treatment, but once treatment is discontinued most children relapse back into their constipation. This may indicate the existence of a defect in colon motility, with a persistent peristalsis problem. The existence of a common neuromuscular disorder should be the base for both bladder and bowel dysfunction (BBD).


OBJECTIVE
To study colonic transit time (CTT) in children and adolescents with refractory constipation and lower urinary tract symptoms (LUTS).


MATERIALS AND METHODS
A total of 15 children (mean age 9.7 years) with refractory constipation and LUTS were evaluated with: standardized medical history; physical examination; bladder and bowel diaries; Bristol stool scale; Rome III criteria; Dysfunctional Voiding Scoring System (DVSS); ultrasound examination of the kidneys and urinary tract, and measurement of rectal diameter; urodynamic evaluation; and a CTT study using radiopaque markers.


RESULTS
Urodynamic features were abnormal in 13 out of 15 children: 10 (66.7%) presented with detrusor overactivity (DO) and voiding dysfunction (VD), two (16.7%) had isolated DO, and one (8.3%) had a VD. The CTT study was abnormal in 12 out of 15 children: nine (60%) presented with slow transit constipation, three (20%) had outlet obstruction, and three (20%) had a normal CTT study. When comparing CTT and LUTD, nine (100%) children with slow transit constipation (STC) and three (50%) with no STC had DO (P = 0.04). Seven (77.8%) children with STC and three (50%) with no STC had VD (P = 0.29). The DVSS scores ranged from 6 to 21. The subgroup with STC had a DVSS score that was significantly higher than that of the subgroup with noF STC (Figure).


DISCUSSION
The present study showed a high prevalence of STC in children and adolescents with refractory constipation and LUTS. This was in accordance with previous studies that have demonstrated a rate of 50-60% of STC in children with refractory constipation. In addition, DO was found to be associated with STC, which raises the chance for the existence of a common neuromuscular disorder to be the base for both bladder and bowel dysmotility. The limitation of this study was the number of participants.


CONCLUSIONS
The present study demonstrated an association between DO and STC.