A: Nighttime bedwetting (enuresis) is a common problem in children. Approximately 5% of all kids are still wetting the bed most nights at the age of 5 and about 5% of those kids stop wetting the bed every year after that. Bedwetting has nothing to do with the strength or weakness of the bladder; it is thought to be related to the maturation of the nerves that lead to the bladder and indicate when to hold or release urine. Your son may have more success staying dry on vacation because sleep schedules and routines are different; he may not be sleeping as long or falling as deeply asleep as he does at home.
Bedwetting alarms are not necessarily going to improve the problem, and they may wake up the family. Instead, have him drink less or nothing after dinner and to use the bathroom before bed; this will likely help him stay dry at night since his bladder will be emptier. Some parents even choose to wake a child to use the bathroom during the night since interrupted sleep for a bathroom trip is better than waking up cold and wet. Also, there is a genetic component to this issue, so there is usually a parent or relative (aunt, uncle, etc.) who also wet the bed as a child and who can talk about when they became dry at night; this may help determine what age your son will also be dry.
Just remember that bedwetting is not something a child can control, so discipline is the wrong answer. It may seem like you son is the only one with the problem, but if there are 100 kids of the same age at his school, there are at least two other 10-year-olds with the same problem. Children will outgrow this with time; only 2% of kids are still bedwetting at 12-years-old and nearly everyone is dry by age 15. Patience is the best treatment.