Sometimes the child's bladder is just too small. It helps to be patient and give your child lots of love. Children who wet the bed can't help it. They don't do it on purpose. Getting mad only makes the problem worse.
Doctors say to just wait.
Don't praise the child for a dry bed or punish the child for a wet bed. Make sure your child goes to the bathroom before bed. Help your child remember to do what the doctor tells them to do. Have your child change the bed or pajamas during the night if they get wet. Or keep a flannel-covered rubber sheet near the bed.