The correlation between constipation and wetting is very commonly overlooked. Sampaio, Sampaio Sousa, Fraga, Veiga, Netto & Barroso (2016) interviewed 829 children and 9% had urinary symptoms. Of those children with urinary symptoms 35% also had constipation. Only 8% of kids without urinary symptoms had constipation alone. Kids that void infrequently and are considered “holders” are more likely to also have constipation. More specific to bedwetting, 12% of bedwetters also had constipation though this was not considered statistically significant.
My opinion: I often see kids for bedwetting with their prior records that say “nighttime wetting only.” Once I start talking with the child, I find out they are too embarrassed to admit to daytime wetting or problems with pooping. Even though there is a low correlation
Sampaio, C., Sousa, A. S., Fraga, L. G., Veiga, M. L., Netto, J. M., & Barroso, U. (2016). Constipation and Lower Urinary Tract Dysfunction in Children and Adolescents: A Population-Based Study. Frontiers in Pediatrics,4. doi:10.3389/fped.2016.00101