Is the child over age 8? If not, back off, it's normal.
Is this a new behavior after something changed in his life: new school, new baby, etc? If so, it should resolve itself as he gets over the stress. Gently reward dry nights and do not punish wet ones.
Has the child been examined for physical causes? If not, make an appointment today.
Have there been other behavior changes? If so, then talk to his doctor about your concerns. Some kids can start wetting after huge upsets in their life - such as being molested or losing a parent. Parents don't always know what's going on and in this case a child psychologist may help.
If he is over age 4, has no physical problems, no new stressors in his life, and hasn't recently started wetting, talk to his doctor about a bedwetting alarm. Retraining his sleeping brain may do the trick.
at 12:11 PM on May. 19, 2009