Urinary Incontinence in Children (cont.)

What causes daytime incontinence?

Daytime incontinence that is not associated with urinary infection or anatomic abnormalities is less common than nighttime incontinence and tends to disappear much earlier than the nighttime versions. One possible cause of daytime incontinence is an overactive bladder. Many children with daytime incontinence have abnormal elimination habits, the most common being infrequent voiding and constipation.

An Overactive Bladder

Muscles surrounding the urethra -- the tube that takes urine away from the bladder -- have the job of keeping the passage closed, preventing urine from passing out of the body. If the bladder contracts strongly and without warning, the muscles surrounding the urethra may not be able to keep urine from passing. This often happens as a consequence of urinary tract infection (UTI) and is more common in girls.

Infrequent Voiding

Infrequent voiding refers to a child's voluntarily holding urine for prolonged intervals. For example, a child may not want to use the toilets at school or may not want to interrupt enjoyable activities, so he or she ignores the body's signal of a full bladder. In these cases, the bladder can overfill and leak urine. In addition, these children often develop UTIs, leading to an irritable or overactive bladder.

Other Causes

Some of the same factors that contribute to nighttime incontinence may act together with infrequent voiding to produce daytime incontinence. These factors include

  • small bladder capacity


  • structural problems


  • anxiety-causing events


  • pressure from a hard bowel movement (constipation)


  • drinks or foods that contain caffeine, which increases urine output and may also cause spasms of the bladder muscle, or other ingredients to which the child may have an allergic reaction, such as chocolate or artificial coloring

Sometimes overly strenuous toilet training may make the child unable to relax the sphincter and the pelvic floor to completely empty the bladder. Retaining urine, or incomplete emptying, sets the stage for UTIs.