1. Overview and definition

 As children grow, they gradually gain control over their urination and defecation. Urine leakage after the age of 5 is referred to as enuresis, nocturnal enuresis (bedwetting) when it occurs at nighttime, and diurnal enuresis when it occurs during the daytime. Stool leakage after the age of 4 is called encopresis. Conversely, pollakiuria is defined as frequent urination, that is, ≥8 times per day, without urine leakage in children aged 5 years or older.

2. Causes

 Nocturnal enuresis typically stems from three main factors:

1. Excessive nighttime urine production, which results from insufficient nocturnal secretion of antidiuretic hormone that normally concentrates and reduces urine output.
2. Low bladder capacity.
3. Difficulty awakening in response to the urge to urinate, as children are physiologically deep sleepers.

 The timing of adequate antidiuretic hormone secretion and bladder development varies among individuals.

 Diurnal enuresis may result from several factors, such as bladder dysfunction and improper toilet training. Many children may have difficulty recognizing the appropriate time to use the bathroom. Even when they feel the urge, they may avoid going if the bathroom feels uncomfortable (e.g., due to fear or darkness), or they may be so engrossed in play or activities that they miss the proper timing.

 The most common cause of encopresis is constipation. When the intestines are filled with stool, softer stool can leak around the hardened mass. Psychosocial factors may be involved.

 Underlying causes of enuresis and encopresis may include kidney, bladder, urethra, spinal cord, endocrine, or nervous disorders. Therefore, various diagnostic tests may be necessary.

 Pollakiuria may be caused by infections, endocrine disorders, or medication side effects. However, most children with pollakiuria do not have an identifiable disease, which is referred to as psychogenic pollakiuria. Despite its name, only about half of cases involve clear psychosocial stress. It is considered a temporary condition causing bladder hypersensitivity and frequent urges to urinate.

3. Treatment and management

 Any physical illness should be treated first. If no physical cause is found, the following approaches are recommended:

・Nocturnal enuresis

 The first-line treatment is lifestyle modification. This includes limiting fluid intake 2–3 h before bedtime and ensuring the child uses the bathroom right before going to sleep. Establishing regular bowel habits and maintaining a consistent sleep schedule with early bedtimes and waking times are also important. Although some families wake their children at night to use the bathroom, this is generally discouraged, as it can disrupt sleep and potentially worsen enuresis. However, waking the child during special occasions (e.g., overnight school trips) may be considered acceptable. If lifestyle changes are insufficient, discuss with the child and family the possibility of introducing medication or enuresis alarm therapy. This therapy involves attaching a sensor to the child’s underwear; when urination begins, an alarm wakes the child, prompting bathroom use. This method helps increase bladder capacity over time.

・Diurnal enuresis

 Treatment involves urotherapy, which includes scheduled bathroom visits regardless of the urge to urinate. On days off, children may practice urine retention to improve bladder control. If urotherapy is ineffective, medication may be considered.

・Encopresis

 Treatment focuses on relieving constipation. Initially, the impacted stool is removed from the rectum. Then, dietary adjustments and medications are used to prevent recurrence, along with guidance to establish healthy bowel habits.

 In enuresis and encopresis, scolding is counterproductive. These conditions often evoke shame and guilt, and self-esteem may decline as children grow older. Verbal criticism increases psychological stress and can worsen symptoms. Instead, children should be encouraged through praise, which fosters confidence and motivation to achieve goals. This principle applies to children with enuresis and encopresis. Adults should consistently offer praise, not only recognizing success but also acknowledging effort and positive behavioral changes. This helps boost self-esteem and supports symptom improvement.

・Psychogenic Pollakiuria

 In this condition, anxiety about urination and excessive attention from family members can become secondary aggravating factors. The child must be reassured that they may use the bathroom as often as needed. Family members should neither criticize nor worry but observe the child calmly. If symptoms persist, medication or psychotherapy may be considered.

HOSOGI, Mizuho

Hosogi Children’s Clinic

Department of Pediatric Psychosomatic Medicine, National Hospital Organization Fukuyama Medical Center