In a 2012 study published in The Journal of Urology, researchers examined the relationship between men’s bowel movement habits and the prevalence of urinary symptoms, such as urinary hesitancy, feelings of not having fully emptied the bladder, and frequent nighttime urination. The study findings showed that men who pooped three times or less each week (aka constipation) were more susceptible to nocturia, which the researchers characterized as waking up for two or more bathroom trips nightly.
Different theories have been proposed as to why constipation-related straining may have us peeing more throughout the night. However the subject has been explored more extensively in kids, as many children tend to voluntarily hold their poop. Pediatric experts at the University of California, San Francisco Department of Urology state that our bladder gets subjected to excess pressure when there’s a buildup of stool hanging out in the colon. As a result, children may be more likely to wet the bed at night.
Researchers have also suggested that clenching the anal sphincter for long periods of time may cause inappropriate contractions of the pelvic floor muscles as well as detrusor-sphincter dyssynergia. Detrusor-sphincter dyssynergia is a urinary condition that has been associated with nocturia.