Development Of Bladder Control And Toilet Training Readiness

Toilet training is a big deal for kids and parents! As a pediatric pelvic floor therapist, you may play a crucial role in guiding families through this process. Understanding how bladder control develops and recognizing the signs of toilet training readiness can make a big impact on family dynamics.

In this blog post, you’ll learn about the stages of bladder control development, the neurological and physiological aspects involved, and how to spot when a child is ready for toilet training.

During infancy and into the first few years of life, children’s bladder control is reflexive. Even with small amounts of urine, the bladder contracts in response to stretch receptors in its walls. First, the external sphincter contracts, reciprocally causing the detrusor muscle to relax. Second, when the sphincter relaxes, the child voids. This reflexive mechanism is the foundation for the more complex bladder control that develops as the child grows.

Bladder control is a complex system involving the peripheral, sympathetic, parasympathetic, and somatic nervous systems. The bladder is controlled by the interactions between the spinal cord micturition center, brain stem, midbrain, and higher cortical centers. In infancy, these neural pathways are still developing. However, even in newborns, there’s cortical arousal in response to bladder distension. As these pathways mature, they allow for more voluntary bladder control.

For effective bladder control, the detrusor muscle and sphincter must work together reflexively. By around three months, babies typically void about every hour. The awareness of bladder sensations and initial control begins in the first to second year of life. As the central and peripheral nervous systems mature, micturition becomes voluntary, with control usually established by age three.

For children to stay, become, and maintain urinary continence, they must have both an intact nervous system and urinary system. Children born with spina bifida or cerebral palsy don’t have intact nervous systems. Some children have structural anatomical variations of the bladder or ureters. Keep both of these systems in mind when working with kids to help set attainable continence goals.

To maintain continence, the urethral resistance pressure must be higher than the bladder pressure. The bladder neck needs support from the surrounding pelvic floor ligaments, fascia, and pelvic floor and sphincter muscles. Additionally, avoiding constant increases in intra-abdominal pressure, such as in kids with cystic fibrosis, is crucial to maintain continence and minimize leakage.

Bladder control occurs when children develop voluntary control over the sphincter muscles, which leads to increased bladder capacity and the child is able to hold more. This is when they learn and develop direct volitional control over spinal reflexes.

Children also need to have the cognitive awareness of the need to void and the ability to identify an appropriate place to do so. They must also have the physical ability to get to the toilet, undress, dress, and flush the toilet.

As children develop control of their sphincters, bladder capacity increases, and they learn direct volitional control over spinal reflexes. For kids with special needs who can’t coordinate all these steps, creating a socially continent schedule is essential.

The voiding cycle has 3 phases, which are each controlled by different neurological pathways and neurotransmitters. Understanding the mechanisms of control can help you to parse out where the incontinence is stemming from.

1. Filling and Storage Phase: During this first phase, the bladder fills and expands at low pressures for two to five hours. In order for children to maintain urinary continence, the bladder outlet must maintain a barrier where the outlet pressure always exceeds the bladder pressure. Sympathetic innervation from T11-T12 inhibits micturition, which is stimulated by norepinephrine.

2. Transition Phase: In this second phase, sensory stretch receptors in the bladder wall and posterior urethra provide a slight perception of the need to void. A child’s ability to recognize these stretch signals indicates bladder fullness. Voluntary inhibition of urination involves contracting the pelvic floor muscles and closing off the bladder.

You need to consider a child’s interoception, which is the ability to regulate and recognize bodily sensations and emotions. In a previous blog, I discussed why interoception is an important aspect to assess when treating pediatric bowel and bladder dysfunction. Children with interoceptive differences may struggle with continence for this reason.

3. Emptying Phase: In this last phase, the detrusor muscle contracts and maintains the contraction until the bladder is empty. Parasympathetic outflow promotes bladder contraction through a cholinergic response stimulated by acetylcholine. Simultaneously, somatic impulses along the pudendal nerve from S2-S4 signal the pelvic floor muscles to relax and external sphincters to open.

As you can see, there are multiple neurological pathways that can get potentially interrupted; one part may be disrupted while the others continue to work. We can help children become continent by understanding these different pathways to differentiate where the dysfunction is and to determine the appropriate respective treatment interventions.

How do you know when a child is ready to toilet train?

Toilet training readiness typically begins around two to three years of age, with most children gaining control by age four.

Look for these signs that a child is ready for toilet training:

• Dry for 2 hours.
• Can dress and undress without help.
• Shows interest in using the toilet.
• Notices when they have a wet or dirty diaper.
• Communicates the need to pee or poop.
• Willingness to interrupt activities to use the toilet.

Of course, children must also have the physical strength and coordination to properly engage the diaphragm, lower abdominal muscles, and pelvic floor. The developmental skills of sitting, standing, and walking are directly related to bowel and bladder function, so functionally balancing these muscle groups significantly affects continence capability.

Children must also have the psychological skills to motivate them for toilet training. They must be willing to learn and have good parental support and encouragement.

Guide parents not to push the process too soon. Life events can often interrupt or delay this process, and that is ok. Advise parents to meet their child at their current developmental stage.

The period of toilet training is critical for parents to be aware of constipation and prevent it. There are two classic times that constipation frequently begins: one, when a child starts eating solids; and two, when a child starts potty training. In next month’s post, I’ll delve into tips for good bowel and bladder health when returning back to school.

Encourage parents to be patient and avoid rushing the process. This is key to successfully toilet train children and maintain their overall well-being. You play a special and trusted role in guiding parents and children through this important developmental stage more effectively.

If you want to learn more about toilet training and treating urinary incontinence, I encourage you to sign up for my self-paced online course Peds Level 1.

If you prefer to participate in this course live, join me on August 24-25, 2024, where you can join in community and learn with other pediatric pelvic floor therapists!