How can I differentiate between primary and secondary enuresis in a child presenting with bedwetting?

Primary enuresis is characterised by a child who has never achieved a sustained period of at least 6 months of nighttime dryness without assistance. In contrast, secondary enuresis occurs when a child who was previously dry at night for 6 months or more begins to wet the bed again. To differentiate between the two, ask if the child had previously been dry at night without assistance for 6 months; if yes, and bedwetting has recurred, this indicates secondary enuresis. Additionally, for secondary enuresis, it is important to enquire about any possible medical, emotional, or physical triggers that might have precipitated the recurrence, such as urinary tract infections, stress, or other health issues. The presence of daytime urinary symptoms (such as frequency, urgency, or daytime wetting) may also suggest an underlying bladder disorder that requires further assessment. A detailed history including the pattern of bedwetting, volume of urine, and any daytime symptoms helps inform the diagnosis and differentiation between primary and secondary enuresis.

In summary, the key differentiator is the history of a dry period of at least 6 months: absence of such a period indicates primary enuresis, while its presence followed by recurrence indicates secondary enuresis.

It is also important to consider and assess for any comorbidities such as constipation or emotional/behavioural problems, which may be more relevant in secondary enuresis.

These approaches align with the NICE guideline on bedwetting in under 19s.