The constipation-UTI correlation

If you’re experiencing constipation, that can be an indicator of an issue with your pelvic floor. And, issues with our pelvic floor can contribute to UTIs. Today, we discuss the constipation-UTI connection from a pelvic floor physical therapist perspective.

First let's take a deeper dive into constipation. The underpinnings of constipation are broken down into two main categories:

1. slow transit constipation
2. pelvic outlet dysfunction

Slow transit constipation refers to the slowed movement of contents through the digestive tract which can be affected by a number of factors such as underlying comorbidities, fiber intake, diet, sedentary lifestyle etc.

What we will discuss more here is pelvic outlet dysfunction, or a disturbance at the outlet that impairs the passage of stool. About 50% of chronically constipated people have pelvic outlet dysfunction.

Let’s explore what causes pelvic outlet dysfunction and how those causes connect and/or contribute to UTI occurrence.

Pelvic floor dyssynergia

By and large, one of the major causes of pelvic outlet dysfunction is something called pelvic floor dyssynergia.

Pelvic floor dyssynergia means your muscles are contracting when they should be relaxing, preventing the elimination of stool.

Find yourself straining and pushing on the toilet? This is probably your culprit. Pelvic floor dyssynergia is the paradoxical contraction (when it should relax) of the puborectalis muscle, preventing elimination of stool. 

The puborectalis muscle is a muscular sling that wraps around the lower rectum as it passes through the pelvic floor and has an important function during the act of having a bowel movement.

To step back, what happens with a proper bowel movement? As stool enters the rectum, your internal anal sphincter involuntarily relaxes and sends your mind the urge to poop. If all social factors are met and you make it to a toilet, next your external anal sphincter and pelvic floor muscles must relax to open up the anorectal angle to allow stool to exit (see photo below). 

With dyssynergia, your body contracts, rather than relaxes, the external anal sphincter and pelvic floor muscles and leads to lots of straining as you try to push past these barriers. Straining itself can exacerbate and cause the dyssynergia as straining will lead to tighter and overactive pelvic floor musculature that have an even harder time to relax with bowel movements.

If this dyssynergia is present with bowel movements, it likely may be occurring during bladder voids (urination) as well. If your pelvic floor is not relaxed while peeing, you may have incomplete voiding and dysfunctional voiding (see article of pelvic physical therapy for more on dysfunctional voiding), both of which can make you more susceptible to UTIs.

Additionally, the straining from constipation can lead to overactive pelvic floor muscles that can contribute to recurrent UTIs as well.

Mechanical outlet dysfunction

This refers to physical blockage of the pathway of stool out of your body. The biggest contributor here: prolapse. Two common prolapse conditions that can cause constipation include:

• A posterior vaginal prolapse (also known as rectocele) is a weakening of the posterior wall of the vagina allowing the rectum to bulge into the vagina.
• A rectal prolapse is a rectum bulging down through the anal canal.

Both disrupt the natural pathway of stool making bowel movements more challenging or trapping stool in the rectum (incomplete bowel movements). Both are also often associated with cystocele (bladder pressing on weak anterior vaginal wall), enterocele (small intestines pressing on weak vaginal wall), and uterine prolapse (uterus descends through the vagina.

Prolapse can disrupt the natural pathway of stool making bowel movements more difficult.

A pelvic floor physical therapist can assess you for all forms of prolapse! Any of these prolapses can lead to incomplete emptying of the bladder as well due to unnatural pressures cinching off the bladder or altering its natural position. And incomplete emptying can lead to increased chance of UTI.

Other connections

Antibiotics can also be a contributing factor of constipation to consider.

An overfull rectum will physically press more on the bladder and lead to increased spasm and obstruction of urine. This spasm or overactivity of the bladder can lead to overactivity/hypertonicity (aka tightening) of the pelvic floor muscles and thus perpetuate dysfunctional bowel and bladder movements due to inability of those muscles to relax. Also, an overfull rectum will independently stress the pelvic floor musculature with its added pressure and contribute to hypertension/overactivity of the pelvic floor muscles. Pelvic floor hypertension is often a contributing factor to UTIs (see article about pelvic floor physical therapy for UTIs).

Conclusion