Giggle incontinence, giggle enuresis or enuresis risoria, is the involuntary release of urine in response to giggling or laughter. The bladder may empty completely or only partially. Giggle incontinence is more common in children than adults, typically appearing at ages 5 to 7, and is most common in girls near the onset of puberty. The condition tends to improve with age, with fewer episodes during the teenage years, but may persist into adulthood. Giggle incontinence is a special form of urge incontinence (an involuntary loss of urine occurring for no apparent reason while feeling urinary urgency, a sudden need or urge to urinate), and is not the same as stress incontinence, which is generally brought on by participating in vigorous sport.
In voluntary urination, the bladder’s normally relaxed detrusor muscle contracts to squeeze urine from the bladder. One study concluded that the cause of giggle incontinence is involuntary contraction of the detrusor muscle induced by laughter. Because the complaint is difficult to reproduce under controlled conditions, its triggering mechanism is not clearly understood, but may be related to cataplexy, a sudden transient episode of loss of muscle tone often triggered by strong emotions.