However, I have to tell you that you're letting your son's success go to your heads. It's premature by at least six months to expect consistent night dryness from a child of your son's tender age. The fact he was dry after periods of sleep for a couple of months is what I'll call a temporary side-effect of daytime training. It was bound not to last. The other factor operating here is that boys are twice as likely as girls to be bed-wetters. No one knows why that is.
Then there's the matter of the message you're sending your son. If I put this gently, you may not get the point: You're making a huge mistake by telling him that bedwetting is wrong. Reacting punitively is not going to help matters and is very likely to make the problem much worse.
You're also headed toward an ever-escalating parent-child power struggle. Being anxious and punitive about bedwetting sets a bad disciplinary precedent.
Children who wet the bed have no conscious control over the problem. Without exception (that I've ever heard of, at least), they are very deep sleepers who don't “hear” their bladder telling them to get out of bed and use the toilet. So, they just release. When they wake up wet, they can't explain it. That applies as well to older kids who still wet.
I encourage you to back off and wait until spring — not because of warm weather, but because he'll be old enough by then to begin having success — maybe. I recommend a “waiting period” of no less than six months between daytime training and attempts to help a child learn nighttime bladder control.
Let him sleep naked from the waist down. That increases the likelihood that when he wets, he'll wake up. For some unknown reason, that usually (but not always) promotes a quicker resolution to the problem.
And be sure to accentuate the positive.
Family psychologist John Rosemond answers parents’ questions on his website at www.rosemond.com.