Even after a child is potty trained, they may still have issues with wetting the bed at night even if they show no issues with control during the day.
According to the Cleveland Clinic, this behavior shouldn't be a concern until the child is older than five and, in those cases, it's usually related to an immature bladder. Boys are twice as likely to have this issue and there is usually some history of bedwetting in the family as well. In most cases, problems can be reduced by improving fluid intake, creating a bathroom schedule, and eliminating potential bladder irritants and other issues.
Parents should first focus on the fluid intake of their child throughout the day and encourage them to drink more often during the earlier part of the day rather than right before bed. School-age children can sometimes fail to hydrate during the day so ask the teacher if they can be allowed to have a bottle of water with them in class so that they aren't overcompensating in the afternoon at home. Work with the child to ensure they have a regular urination schedule that occurs every few hours and just before bedtime. Don't forget to stay positive and encouraging throughout the process.
Once the proper routine is in place, parents should work on eliminating other issues that might be causing problems for their child while they sleep. Several common ingredients like caffeine, citrus juice, and artificial flavors, dyes, and sweeteners can irritate the bladder and cause the sudden need to urinate. Constipation, meanwhile, is responsible for about one-third of bedwetting cases and children are unlikely to tell their parents about this problem on their own.
Although rare, bedwetting could also be a symptom of a more severe condition so if a child that has never had a problem with it before suddenly starts, consult a doctor for treatment. In most cases, bedwetting will resolve on its own over time.