Over the years, researchers have studied many different causes of bedwetting, with no single cause emerging as a primary factor. Now we understand that bedwetting (scientifically referred to as ‘primary nocturnal enuresis’) is actually multifactorial, and it usually results from a combination of issues. It is important to understand what medical factors are at work, as you can then decide an appropriate approach to treatment.
Sleep or Arousal Disorder – Often times, children with bedwetting issues are described as “deep sleepers” by their parents or caregivers, meaning they are not easily roused from sleep. Past studies on sleeping patterns or sleep arousal have proven to be controversial and often inconclusive. It appears instead that wetting occurs at all stages of the sleep cycle, and although the exact reasons are not well understood, it seems most children are not easily roused from sleep at any point in the cycle.
Food Sensitivities - A small percentage of children are sensitive to certain foods that can contribute to nocturnal enuresis. These children may benefit from eliminating foods such as citrus and carbonated drinks.
High Urine Production - In most people, the release of a hormone called vasopressin reduces the amount of urine produced at night. Some children actually release less vasopressin at night, leading to a higher urine volume. These children produce more urine than their peers and are more prone to bedwetting - especially when other factors are present.
Low Functional Bladder Capacity - Another common factor in children affected by bedwetting is a low functional bladder capacity. These children have less forewarning of the need to urinate and feel more urgency as a result. When a child's functional bladder capacity is low they are less able to hold a normal amount of urine at night, and may also experience daytime symptoms.
Irregular Bowel Movements - Sometimes children who wet are actually suffering from bowel problems, such as irregular bowel movements or constipation. When the rectum is full the bladder's expansion may be restricted, and this can result in decreased sensitivity to bladder fullness.
Other less common causes of bedwetting include anatomic abnormalities, endocrine disorders and urinary tract infections.