Infants empty their bladders by reflex. When the bladder fills and stretches beyond a certain point, it signals the spinal cord, which triggers the sphincter to relax and the bladder to contract. Young children gradually develop control over this process. Bladder stretching registers consciously as discomfort, and the brain learns to suppress the reflex. The more the bladder stretches, the more urgent the desire to urinate.
Incontinence can occur for many reasons.
Urinary tract infections, vaginal infection or irritation, constipation, and certain medications may cause temporary incontinence. Anything that damages the nerves or muscles at the bottom of the pelvis, or the pelvic floor, increases the risk. Anatomical differences between the sexes affect the underlying causes and the tendency for certain types of incontinence to develop. Urge incontinence is the involuntary loss of urine associated with a strong desire to urinate. The person can't control urination long enough to get to the toilet in time.