They don't close enough to affect the urine stream. Of course, if you have any questions about the amount, color, or frequency of your baby's urination, you should call the doctor. Turn off Animations. Ask someone you trust to take care of the baby for an hour or two. Place one tissue into your baby's diaper to absorb the urine and make it easier to see. Both boys and girls can have a little blood in their diaper, but for different reasons.