Dysfunctional Voiding in Children: A Hidden Cause of Recurrent Urinary Tract Infections

Urinary tract infections (UTIs) are one of the most common health problems in children. While many people think UTIs are caused only by bacteria, the way a child empties their bladder can also play a major role. In many neurologically normal children, repeated UTIs are linked to a condition called dysfunctional voiding (DV). One important factor behind dysfunctional voiding is diaphragm–pelvic floor dyscoordination, which occurs when the muscles involved in breathing and bladder emptying do not work together properly. 

To understand why this matters, it helps to know how normal urination works. When the bladder fills with urine, the bladder muscle, called the detrusor, stays relaxed. When it is time to urinate, the detrusor contracts while the pelvic floor muscles and external urethral sphincter relax. This coordinated action allows urine to flow out easily and completely. The diaphragm and abdominal muscles support this process by helping regulate pressure within the abdomen. 

In children with dysfunctional voiding, this coordination breaks down. Instead of relaxing during urination, the pelvic floor muscles and external urethral sphincter tighten or remain partially contracted. This creates a functional blockage at the outlet of the bladder. The bladder must work harder to push urine out, and in many cases it cannot empty completely. 

When urine remains in the bladder after voiding, it creates an ideal environment for bacteria to grow. This leftover urine, known as post-void residual urine, acts like a reservoir where bacteria can multiply. Over time, this increases the risk of recurrent UTIs. Children with dysfunctional voiding often show interrupted or staccato urine flow patterns during testing, which reflects the repeated tightening and relaxing of the pelvic floor muscles during urination. These abnormal voiding patterns can also increase bladder pressure, which may worsen conditions such as vesicoureteral reflux (VUR), where urine flows backward toward the kidneys. 

Another common problem seen with dysfunctional voiding is constipation. The bladder and bowel are closely connected. When stool builds up in the rectum, it can place pressure on the bladder and interfere with normal bladder emptying. Constipation can also contribute to abnormal pelvic floor muscle activity. This combination of bladder and bowel dysfunction significantly increases the likelihood of recurrent UTIs. Research has found that children with bladder and bowel dysfunction have more than double the risk of recurrent UTIs compared with children who do not have these issues. 

A growing body of research has focused on the role of the diaphragm in pelvic floor function. The diaphragm forms the top of what is often called the abdominal canister, while the pelvic floor forms the bottom. These structures work together with the abdominal muscles to maintain pressure and support normal movement. In healthy individuals, the diaphragm descends during inhalation, while the pelvic floor responds with coordinated movement and relaxation. 

Many children with dysfunctional voiding develop poor breathing habits. Instead of breathing deeply with the diaphragm, they may brace their abdominal muscles and tighten their pelvic floor muscles at the same time. This pattern creates unnecessary tension throughout the pelvic region. During urination, the child may continue to hold these muscles tight, making it difficult to empty the bladder completely. 

Because of this connection, diaphragmatic breathing has become an important part of treatment for dysfunctional voiding. Diaphragmatic breathing teaches children to breathe deeply into their abdomen rather than their chest. As the diaphragm moves downward during inhalation, the abdominal wall relaxes and pelvic floor tension decreases. Over time, children learn how relaxation feels and how to apply it during urination. 

Studies have shown promising results from combining diaphragmatic breathing with pelvic floor muscle retraining. In one study involving children between five and thirteen years old with dysfunctional voiding, researchers used diaphragmatic breathing exercises along with pelvic floor retraining. After twelve months, sixty-eight percent of the children were free from UTIs, eighty-three percent no longer experienced urinary incontinence, and all participants recovered from constipation. Most children also developed normal urine flow patterns on testing. These findings suggest that correcting breathing and pelvic floor coordination can produce meaningful improvements in bladder function. 

Pelvic floor muscle retraining focuses on teaching children how to voluntarily contract and relax their pelvic floor muscles. Many children with dysfunctional voiding are unaware that they are tightening these muscles at the wrong times. Through guided exercises, they learn to identify pelvic floor tension and practice relaxation. Consistent practice helps retrain the nervous system and promotes healthier voiding habits. 

Biofeedback with rehabilitative ultrasound imaging (RUSI) can be used to enhance this learning process. RUSI allows children to see their muscle activity in real time. As children learn to relax their pelvic floor muscles, they receive immediate visual feedback, which helps reinforce proper muscle control. 

Research has shown that RUSI can improve urine flow rates, reduce post-void residual urine, and normalize voiding patterns. Studies have also demonstrated significant reductions in recurrent UTIs after RUSI treatment. Importantly, these improvements often become more noticeable over longer treatment periods, suggesting that lasting changes require consistent practice and reinforcement. 

RUSI can be used both for assessment and treatment. During evaluation, therapists can observe whether the pelvic floor moves correctly during contraction and relaxation. Some children demonstrate paradoxical movement, meaning they tighten the pelvic floor when they are supposed to relax it. Ultrasound helps identify these abnormal patterns and guides treatment planning. 

During therapy sessions, ultrasound serves as a powerful biofeedback tool. Children can watch the bladder base and pelvic floor move on the screen while practicing exercises. They can also see how much urine remains in the bladder after voiding. This visual feedback helps strengthen the connection between relaxation and complete bladder emptying.  

Pelvic floor physical therapy is one of the most effective treatment approaches for dysfunctional voiding and combines several strategies. This includes education on normal voiding, scheduled bathroom visits every two to three hours, proper toilet posture, adequate hydration, and treatment of constipation. For children with confirmed dysfunctional voiding, diaphragmatic breathing and pelvic floor retraining are commonly added. Rehabilitative ultrasound can provide additional support. 

The key message is that recurrent UTIs are not always caused by infection alone. In many children, underlying problems with bladder emptying contribute to repeated illness. Diaphragm–pelvic floor dyscoordination plays an important role in dysfunctional voiding by preventing complete relaxation of the pelvic floor during urination. By addressing this coordination problem through breathing exercises, pelvic floor retraining, and ultrasound-guided therapy, pelvic floor physical therapists can target the root cause of incomplete bladder emptying. This approach not only improves urinary symptoms but can also significantly reduce the risk of recurrent UTIs, helping children achieve better long-term bladder and bowel health. 

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Disclaimer: This blog is here for your help. It is the opinion of a Licensed Physical Therapist. If you experience the symptoms addressed you should seek the help of a medical professional who can diagnose and develop a treatment plan that is individualized for you.