Accidents, periodic episodes of urinary or fecal incontinence, are generally a normal part of toilet training  and are usually not a sign of serious medical issues. Accidents that occur with additional problems, such as pain when urinating or defecating, chronic constipation, or blood in urine or feces, should be evaluated by a pediatrician. The prevalence of nocturnal enuresis, also known as bed wetting, may be as high as 9.7% of seven-year-olds, and 5.5% of ten-year-olds, eventually decreasing to a rate of about 0.5% in adults.: 47 