The word Enuresis means “involuntary and persistent emission of urine during the day, night or both, after an age at which the child should have learned to control urination (usually between four and five years) and not there are signs of organic pathology.”
When the child meets the following diagnostic criteria:
Repeated emission of Urine in bed or on clothes (involuntary or intentional)
Types and subtypes
Generally, there are two basic forms of Enuresis: primary and secondary. These categories can be divided into diurnal, nocturnal and mixed Enuresis. Likewise, based on the frequency parameter, it is possible to distinguish between regular and sporadic Enuresis. These types and subtypes of Enuresis indicated are explained below.
Depending on the beginning or progress of the problem, a difference is made between primary or secondary Enuresis. The first refers to the child having never acquired voluntary control of urination. Whereas when we refer to secondary Enuresis, we mean that the child has managed to control urination for at least six months and begins to have episodes of incontinence after this control.
Enuresis can be diurnal, nocturnal or mixed. The first incontinence episodes occur during the day when the child is awake. The nocturnal occurs when the child sleeps at night, while the mixed refers to the confluence of the previous two when Urine leaks both during the day and at night when asleep.
Regarding the frequency variable, it is possible to distinguish between regular Enuresis when urination occurs continuously as a chronic and daily event and sporadic when it occurs intermittently.
The prevalence of Enuresis is between 15 and 20% in 5-year-old children, resolving spontaneously at 15% per year and presenting in 1-3% in adolescence and adulthood.
The most frequent type of Enuresis is primary, which appears between 75-80% of children, compared to secondary, which represents 20 or 25% of the clinical population. Primary Enuresis is present more frequently in males. It usually occurs regularly and remits with age in a high proportion. It is linked to a greater extent with developmental factors, physiological dysfunction or learning factors. While secondary Enuresis appears more frequently in the female gender, more sporadically, and is associated with the delay in the acquisition of daytime continence, with a higher incidence of emotional problems or stressful events in its aetiology. However, no gender differences are observed in the presence of mixed Enuresis.
Studies have also found that nocturnal Enuresis is more common than daytime Enuresis; spontaneous remission appears more in primary nocturnal Enuresis than in secondary.
Enuresis is multicausal, resulting in the interaction of different factors that act in combination and differently in each child, but none of them individually can fully explain the phenomenon. Among them, physiological factors (functional capacity, altered waking response and inhibitory deficit) are hereditary, maturational, learning or social.
Studies carried out with twins, and epidemiological data affirm a specific genetic predisposition in the development of nocturnal Enuresis. However, the relationship between the identified genes and the phenomenon has not been determined precisely.
Alteration in the wake-up response. Children with Enuresis have a higher level of arousal to react to external and internal stimuli (bladder distension and detrusor contraction); that is, they have difficulty waking up when the bladder reaches its functional level.
Nocturnal Enuresis in children often has nocturnal polyuria (secretion of large amounts of Urine). The explanation that is due to this relationship is attributed to a deficit of vasopressin (the hormone responsible for sending signals to the kidney, so that urine production is inhibited). When there is a lack of this hormone, a more significant amount of Urine is produced in the kidneys, which exceeds the functional capacity of the bladder, causing the enuretic episode.
It refers to the tendency of the bladder muscle to contract involuntarily and suddenly when the bladder is not yet complete, causing Leaks of pee during the day and night. This instability is attributed to the brain’s lack of control over the bladder muscle.
Functional capacity of the reduced bladder: “small bladder”. Children learn to empty their bladder when faced with low volumes of Urine. Therefore, they urinate more frequently and urgently. Although evidence has been found in favour of the relationship between nocturnal Enuresis and the functional capacity of the bladder, it has not been possible to demonstrate it precisely.
They were delayed in the maturation and development of the physiological mechanisms involved in continence. This approach has no consensus because the specific agents involved or how they work have not been determined.
Family training in bladder control. The behavioural theory highlights the role of learning in the acquisition of nocturnal continence. This theory posits that children with secondary Enuresis fail to understand the sphincter contraction response during sleep because inhibitory control learned during the day is not transferred to sleep or because the amount of Urine stored exceeds capacity limits. However, these children do not identify the physiological signs of bladder fullness and distension (stimuli that warn of the need to urinate), so they do not wake up when the urination reflex is triggered, and they wet the bed. Failure to learn sphincter control has been associated with little social reinforcement from the environment.
Stressful life situations
Stressful childhood experiences, such as a parent’s death, divorce, change of address or school, the birth of siblings, school traumas, sexual abuse, hospitalisations, etc., are related to a higher frequency of secondary Enuresis.
In cultures, especially in the West, a more significant presence of Enuresis has been found in lower social classes.